Cambridge Centre for Risk Studies
Scenario Best Practices
DEVELOPING
SCENARIOS FOR
THE INSURANCE
INDUSTRY
Acknowledgements
Cambridge Centre for Risk Studies gratefully acknowledges
Lighthill Risk Network for supporting the research eorts
summarised in this report. The Centre is grateful for the
expertise provided by our research team, collaborators, and
subject matter specialists. Any misinterpretation in use of the
advice provided is entirely the responsibility of the Cambridge
Centre for Risk Studies.
Report Citation
Cambridge Centre for Risk Studies, in collaboration with
Lighthill Risk Network, 2020. Developing Scenarios for the
Insurance Industry. Cambridge Centre for Risk Studies at the
University of Cambridge Judge Business School.
or
Strong, K., Carpenter, O., Ralph, D. 2020. Developing
Scenarios for the Insurance Industry. Cambridge Centre for
Risk Studies at the University of Cambridge Judge Business
School and Lighthill Risk Network.
Cambridge Centre for Risk Studies
University of Cambridge Judge Business School
Trumpington Street
Cambridge
CB2 1AG
United Kingdom
Website and Research Platform
www.jbs.cam.ac.uk/risk
Research Team
Dr Andrew Coburn, Chief Scientist
Professor Daniel Ralph, Academic Director
Simon Rue, Director of Research & Innovation
Dr Michelle Tuveson, Chairman & Executive Director
James Bourdeau, Geopolitical Risk Research
Oliver Carpenter, Lead Environmental Risk Research
Jennifer Copic, Lead Governance Risk Research
Dr Jennifer Daron, Lead Technology Risk Research
Ken Deng, Lead Financial Risk Research
Timothy Douglas, Risk Modelling
Tamara Evan, Lead Geopolitical Risk Research
Taryn Hubbard, Risk Research
Oliver Pearson, Risk Markets Research
Dr Andy Skelton, Lead Risk Modelling
Kayla Strong, Lead Scenario Analytics
Dr Timothy Summers, Senior Data Scientist
Jayne Tooke, Communications and Events
William Turner, Data Science
Lighthill Risk Network
LM01.01.02
The Leather Market
11-13 Weston Street
London, SE1 3ER
United Kingdom
Website
https://lighthillrisknetwork.org/
Members
Matthew Eagle, Managing Director,
Head of GC Analytics (Guy Carpenter)
Premal Gohil,
Head of Innovation Partnerships (Liberty Mutual)
Paul Kaye, Head of Actuarial Practice (Aon)
Shree Khare,
Group Head of Catastrophe Research (Hiscox)
Trevor Maynard,
Head of Innovation (Lloyd’s of London)
Andrew Mitchell,
Head of Catastrophe Modelling (MSAmlin)
Delimoma Oramas-Dorta,
Catastrophe Risk Analyst (Guy Carpenter)
Cameron Rye, Research Manager (MSAmlin)
David Singh, Head of Exposure
and Portfolio Management (MSAmlin)
Keith Smith,
Research and Development Manager (Lloyd’s of London)
Dickie Whitaker,
Chief Executive Ocer (Lighthill Risk Network)
The views contained in this report are entirely those of the research team of the Cambridge Centre for Risk Studies, and do not imply
any endorsement of these views by the organisations supporting the research, or our consultants and collaborators. The results of the
Cambridge Centre for Risk Studies research presented in this report are for information purposes only. This report is not intended
to provide a sucient basis on which to make an investment decision. The Centre is not liable for any loss or damage arising from its
use. Any commercial use will require a license agreement with the Cambridge Centre for Risk Studies.
Copyright © 2020 by Cambridge Centre for Risk Studies.
Cambridge Centre for Risk Studies
Scenario Best Practices
DEVELOPING
SCENARIOS FOR
THE INSURANCE
INDUSTRY
Contents
1
Introduction 5
1.1 The Insurance Industry 5
1.2 Why Use Scenarios? 5
1.3 Report Rationale and Intended Audience 6
1.4 A Framework for Scenario Development 7
2
Understanding Scenarios 8
2.1 What is a Scenario? 8
2.2 Types of Scenarios 9
3
Using Scenarios in the Insurance Industry 15
3.1 General Scenario Uses 15
3.2 Insurance Use Cases of Scenarios 17
3.3 Allocating Risk Capital 20
4
Shock Risk Scenario Development: Insurance Stress Testing 22
4.1 A Checklist for Scenarios 22
4.2 Scenario Development: a Stress Test Perspective 23
4.3 Considerations and Constraints 30
5
Scenario Development Case Study: Business Blackout 33
6
Future Perspectives on Scenarios 37
7
Glossary 38
8
References 40
Cambridge Centre for Risk Studies
4
Scenario Best Practices: Developing Scenarios for the Insurance Industry
1. Introduction
1.1 The Insurance Industry
The insurance industry comprises companies that
provide risk management by underwriting the risks of
individual entities and pooling them to spread the risk.
An insurance contract guarantees that, on the occurrence
of a specied uncertain future event, the insurer provides
a payment to the insured, and thereby assumes the risk.
In return, the insured (or policyholder) pays a premium,
or a regular fee, to the insurer for providing the coverage.
Insurance is critical in providing nancial security to
people and organisations performing their daily activities
and operations; or undertaking new and risky ventures.
There are several classes of insurance available to
accommodate a diverse range of customers with an array
of risks, which are often categorised by their asset type or
the entity being insured. Examples include property and
casualty, accident and health, or auto insurance.
1
In addition to oering traditional coverages for known
risks, supported by comprehensive industry experience
and understanding of their occurrence, insurers must
also continually adapt to emerging and uncertain risks.
Today, such risks are manifesting at an unprecedented
rate as the world is challenged by growing complexity
and interconnectedness between systems. To full the
consequent demand for insurance coverage against
emerging risks, insurers must rst evaluate such
uncertainty and ensure they can withstand potential
losses and operate sustainably. The insurance industry
shares key nancial and operational risk exposures with
the wider nancial sector, but is also uniquely exposed
to insurance risk, so internal assessments of risk must
account for the complexity of interactions between
both an insurer’s assets (premiums invested to cover
liabilities) and liabilities. One means of planning for
the future is using scenario analysis (or ‘stress testing’),
a longstanding practice within the industry, but which
continues to grow in importance as the market becomes
more aware of its benets and regulatory requirements
call for robust internal risk management.
1.2 Why Use Scenarios?
Scenarios are stories about how the future might
develop, aimed to stimulate exploration, understanding,
and discussion. Based on a coherent set of assumptions
about key deterministic relationships and driving forces,
scenarios describe plausible futures that are intended
to be scrutinised and debated. In the context of risk,
scenarios provide a tool to cope with uncertainty,
especially in the case of risks that are not well understood
or cannot be quantied or even identied. They provide
a systematic method for exploring how a complex and
diverse array of risks may impact an organisation, sector,
or economy; or in other words, how resilient these
systems are to potential disruptions. Scenarios question
whether organisations or communities can adapt to,
and even capitalise on, future changes, and stress their
existing capabilities to respond. This understanding
can be applied to support and rationalise decision
making about the future, and facilitate reporting,
management, and mitigation of risks. Scenarios are
valued for supporting creative thinking about plausible
futures, rather than attempting to accurately predict
individual outcomes.
In the insurance industry, these tools continue to
evolve in response to advancing consideration and
regulation of enterprise risk management, both within
the industry and for the insureds that the industry
indemnies. Scenarios are increasingly being used by
underwriters, analysts, risk managers, actuaries, and
other stakeholders in the (re)insurance community to
better understand the characteristics and consequences
of unknown, uncertain, or unexpected future events.
A critical distinction is made between scenarios that
examine emerging trends, which are of concern for
long-term strategic planning; and those that consider
catastrophic shocks, which trigger severe loss across a
potential range of insurance classes, and so represent
acute operational risks. This report is primarily written
to address the latter, and on the design and uses of shock
risk scenarios, which are increasingly in demand to
overcome the challenges posed in today’s and the future
risk landscape.
1. For a complete listing of the types of insurance, please refer to Multi line Data Denition
initiative (Cambridge Centre for Risk Studies, in collaboration with Risk Management
Solutions, Inc. 2018
5
Cambridge Centre for Risk Studies
1.3 Report Rationale and Intended Audience
This report intends to outline best practices for scenario
analysis within the insurance community, and to provide
a practical framework to assist practitioners engaging
with shock scenario development.
Within the report, we explore key features of, and
commonalities and dierences between, insurance
specic scenarios, and suggest how and for whom they
can be used eectively. Due to the varied applications
of scenarios and their associated development
methodologies, we focus the methodology discussion
on shock risk scenarios, and draw commonalities
from various shock scenario development techniques.
As a variety of scenario use cases have unique
requirements and maturity in the practice, development
methodologies do vary. However, we propose that
there is a general process which can be adapted and
modied for these various uses. By providing key
criteria and considerations for scenarios in the form of a
scenario development framework, we hope to equip the
reader with the necessary tools and context to develop
coherent, comprehensive, and intelligible scenarios,
which therefore eectively full their intended purpose.
This report provides insurance-specic
recommendations for scenario development, and
has been published in parallel with another report
2
which similarly outlines best practices for scenario
development in the disaster risk reduction community.
The insurance industry has a rich expertise in risk
assessment tools to price risk, employing scenarios
that tend to be expert-driven, scientically supported,
and product oriented. In contrast, within the diverse
community of disaster risk managers, scenarios
often serve to explore and incorporate the culture
and experience of various stakeholders in a more
participatory approach, for which emphasis may
be placed as much on what is learnt in the scenario
process as the end result. Developing the two reports in
parallel has provided valuable insight into the merits of
contrasting scenario approaches and has informed the
best practices advocated in both.
Report Aims
This report aims to address scenario best practices
through the following considerations:
1
The role scenarios play within the
insurance community;
2
The common and contrasting characteristics and
typologies of scenarios;
3
How scenarios are currently employed and might be
further or better used in methodologies to address
emerging risks;
4
Current scenario limitations and critiques specic to
the insurance community;
5
Stress test scenario guidance for catastrophe
risk analysis;
6
How scenario development and applications might
adapt in the future.
2. Report titled Scenario Best Practices: Developing Scenarios for Disaster Risk Reduction
(Cambridge Centre for Risk Studies, in collaboration with Lighthill Risk Network 2020)
6
Scenario Best Practices: Developing Scenarios for the Insurance Industry
1.4 A Framework for Scenario Development
Within this report, we propose a framework for scenario
development that denes eight core steps, outlined in
Figure 1 and discussed in further detail in Section 4.
This framework is intended as a point of reference to
assist and ensure ecacy in the scenario process, rather
than as a prescriptive method that must be followed
absolutely. Further, while it outlines a linear step-by-step
structure for clarity, we encourage the scenario process
to be an iterative one, in which stakeholder engagement
provides opportunities for review and revision to ensure
it succeeds in fullling its aims.
Step 1 Scope the Risk
Identify the risk to be addressed, or, if the risk is uncertain
or unknown, dene the issues or vulnerabilities that the
scenario exercise aims to expose. In the latter case, the risk
may be identied later in the process. This contextualises
the objectives and resultant decisions of the analysis.
Step 2 Conduct Background Research
Research the topic dened in Step 1 by consulting
relevant sources of (scientic) knowledge and all
associated stakeholders within and beyond the insurance
industry. If possible, consider each dimension of risk:
hazard, exposure, and vulnerability, to recognise how and
where impacts occur.
Step 3 Frame the Scenario(s)
Consider and dene the key aims, benets, and
characteristics of a scenario and its process.
Figure 2 outlines some of the key questions the
developer should ask when framing their scenario.
Sections 2 and 3 provide the context to inform
these considerations.
Step 4 Develop Candidate Scenarios
Compose a series of candidate scenarios that capture
a range of plausible futures. Summarise scenarios with
brief outlines and key variables, and explore contrasting
characteristics. Select scenarios to progress that will
challenge and achieve the desired objectives.
Step 5 Develop a Narrative
Expand the selected scenarios with descriptions
that are interesting, challenging, and plausible for
all stakeholders. Account for all dimensions of a
future event, including context, triggers, timelines,
geography, responses, and implications.
Step 6 Assess Impacts and Materiality
Assess the impacts within the insurance industry and
in wider macro systems. Consider complexities and
interconnectivities that may cause cascading impacts
beyond the expected. Dene what constitutes a material
impact in order to focus the analysis on materially aected
assets and areas of business.
Step 7 Communicate and Act
Communicate the key ndings to stakeholders via
meaningful qualitative and quantitative outputs. The
content and complexity should be tailored to the
audience. Include a clear indication of the extent to
which the results can be relied on to inform decisions and
actions to address the risk.
Step 8 Evaluate and Update
Evaluate whether the objectives of the exercise have been
achieved and iterate the process with stakeholder input to
ensure or enhance ecacy. Be aware that the possibility and
character of a scenario will change as controlling factors
evolve, as will its impact as the industry advances, and so it
should be updated to maintain relevance and utility.
Figure 1: Scenario development framework for the insurance industry
7
Cambridge Centre for Risk Studies
2. Understanding Scenarios
2.1 What is a Scenario?
Scenarios are descriptions of potentially plausible events
that may occur in the future, leading to a particular
set of outcomes. They are based on assumptions about
key driving forces, interconnections, and relationships,
and have the ability to capture the uncertainties and
complexities of a system in a coherent manner. Scenarios
are not intended to comprehensively describe the
future, but rather to highlight focal elements of dierent
plausible futures and to highlight the key factors that
will drive future developments. Sometimes the terms
scenario, projection, and prediction (as well as others
such as forecast and outlook) are used interchangeably,
but while all are tools to investigate the future, each is
nuanced in its meaning. A prediction can be dened as
a subjective (probabilistic) statement that something
will happen in the future, while a forecast is the most
likely expected development.
3
In contrast, a projection is
a (probabilistic) statement that something will happen
under certain conditions, allowing for signicant changes
in the boundary conditions that might inuence a
prediction. A scenario-based projection is a hypothetical
construct of what could possibly happen conditional
upon fundamental assumptions.
4
These assumptions
allow some of the uncertainties that complicate more
exact statements on the future to be set aside for the
benet of a scenario exercise. The dimensions of what
constitutes a plausible event changes as external forces
shift. As a result, the scenario process is inherently an
evolving one, and scenarios which have been developed
and are relied upon should be maintained and updated
regularly to reect current conditions.
Sometimes scenario development and scenario analysis
(also called scenario ‘thinking’ or ‘planning’) are
dierentiated. Development means speculating about
the uncertainty surrounding the future and envisaging
dierent plausible future outcomes, or, in other words,
to create ’memories of the future’.
5
Scenario development
is the necessary foundation for scenario analysis, and
the two are closely linked. Scenario analysis can be
understood as the integration of scenarios into decision
making. Here, we explore both scenario development
and analysis together as the scenario process and use the
terms collectively.
The Probable, Possible and Plausible
When considering the future, we often add
‘probability’, ‘possibility’, or ‘plausibility’
qualications to emphasise relevance or importance.
These notions are implicitly dened, but often
not clearly dierentiated and so are confused. Is a
plausible future also probable? Can one future be
more plausible than another? Should any conceivably
possible future be considered? Care should be taken
in using these terms in the description of scenarios.
Key elements of the three qualiers are summarised
here to establish a distinction between them, but this
concern cannot be resolved by reducing each to a
denition. Scenario users should note that these terms
do not have any universal value, and so should ensure
the distinction between them is made suciently clear
to be useful.
6
Probability refers to the concept of chance and
likelihood, leading to an ordinal ranking of more or less
likely futures. Any future is possible, but the selection
of a probable or improbable scenario depends on
the application.
Possibility is a claim of reality; whether a future
is potentially realisable or not. It is a binary
distinction but may be challenged by absolute
(violation of established laws) or contingent (lack of
realism) reasons.
Plausibility addresses the structure of an argument
and places value on the credibility of a future, which can
hold true even though the future itself may be factually
fallacious. This is therefore a cognitive notion. Scenarios
are challenged by the dierence in interpretation of
plausibility between developers and stakeholders.
3. (MacCracken 2001) 4. (MacCracken 2001; Van Vuuren et al. 2012)
5. (Mietzner and Reger 2005; Schwartz 1997) 6. (Van der Helm 2006)
8
Scenario Best Practices: Developing Scenarios for the Insurance Industry
2.2 Types of Scenarios
Scenario design and development processes can be
commonly distinguished and classied, based on
the development process, their purpose, or certain
characteristics.
7
In practice, these typologies are rarely
binary or independent, and instead can be imagined
as a multi-dimensional matrix with unique outcomes.
This section proposes a series of distinctions which
are commonly used to dene scenarios. We encourage
practitioners to consider them as they construct
scenarios in the context of their scenario aims, within
the process of ‘Framing the Scenario(s)’ (Step 3 in the
Scenario Development Framework). These typologies
are illustrated in Figure 2, and discussed in detail within
this section.
Aid Communication Demonstrate Due Diligence Identify Bias Sensitivity Analysis Addressing Uncertainty
To contextualise complex
risks and promote
stakeholder understanding
To assess risk exposures
and understand their
nancial implications
To explore partialities
that stakeholders may hold
towards certain decisions
To investigate the power
and variance of controlling
variables on a risk
To expand understanding
of the range of
plausible outcomes
Trend Risk Scenario Shock Risk Scenario
Slow-onset, trend phenomena
that emerge gradually over time
Sudden-onset, shock events
that occur quickly or unexpectedly
Exploratory - To ask ‘what if?’ Normative - To ask ‘what for?’
To stimulate imaginative thinking about the future
and widen understanding of available options
To better understand the path to desirable futures
and evaluate the impact of decisions
Figure 2: Framing a scenario – scenario typologies and applications
What is the scenario for?
How can the scenario benet stakeholders?
On what timescale does the risk materialise?
Which is the more important scenario outcome?
Who owns and contributes to the scenario process?
Understanding Tail Risks Understanding Emerging Risks Strategic Planning Accumulation Management
To identify and understand extreme,
low probability risks
To imagine and comprehend
new or evolving risks
To dene a resilient strategy
for the future that alleviates risks
To explore possible extreme or maximal
correlated losses to insurance portfolios
Participatory - Bottom-up, co-production of knowledge Expert-Driven - Top-down, analytical
To incorporate stakeholder culture, knowledge,
and experience in the process and end product
To deliver rigorous scientic descriptions
of plausible futures to decision makers
Probabilistic Deterministic
To estimate the likelihood of occurrence
based on the variance of quantied causal parameters
To speculatively explore phenomena
that involve a high degree of uncertainty
Is the scenario required to dene the likelihood of an outcome?
7. E.g. (Mietzner and Reger 2005; Henrichs et al. 2010; Van Vuuren et al. 2012)
9
Cambridge Centre for Risk Studies
Trend Risk Versus Shock Risk Scenarios
Scenarios can be developed to consider either sudden-
onset, shock events that emerge quickly or unexpectedly,
or slow-onset, trend phenomena that emerge gradually
over time. The type of risk dictates how the scenario is
developed and how it may be used.
Trend risks require users to consider temporality and
identify both short-term signals and long-term impacts.
The latter are likely to be less noticeable than short-
term events and are dicult to align with organisational
decision making, which tends to focus on much shorter
future outlooks; as a result, it can be more dicult to
incentivise mitigation measures for long-term threats.
If eective action is taken, there is the benet of having
enough time to determine the best method to mitigate or
alleviate the risk. Trend risks are typically not insurable
yet are a topic of increasing interest within the insurance
sector, for example, as seen in the corporate uptake of an
Environmental, Social, and Governance (ESG) agenda,
and in response to growing awareness of the increasingly
pronounced impacts of climate change. Insurers are
increasingly needing to make decisions on how to
address trend risks, whether it be through an adaptive
process to keep losses within an insurable window, or
the discontinuation of certain insurance policies. To best
support these decisions, trend risk scenarios remain an
important component of scenario analysis, regardless of
whether the risk is currently insured.
In contrast to trend risks, shock risks are sudden events
which may not have been anticipated and trigger impacts
that materialise rapidly. The focus of these scenarios is
The Origin of Trend Scenarios
Trend risk scenarios have historically been used
within operational or strategic planning and have
roots in policy and operational settings. The Cold
War futurist, Herman Kahn, and others at RAND
Corporation, are regarded as among the founders of
the construction and use of scenarios in the 1950s
and 1960s, primarily in the security arena (e.g., how
a country would function after a nuclear conict),
and encouraged the philosophy of how to ‘think the
unthinkable’.
8
He described a scenario as:
“a set of hypothetical events set in the future
constructed to clarify a possible chain of causal
events as well as their decision points”.
9
Other notable research was being
undertaken at the time by the
Stanford Research Institute,
who oered long-range planning
facilities to support their military
and business consulting. They were
among the rst to formalise and
utilise scenario planning techniques
for decision making by businesses
and governments.
Kahn’s scenario methodology
used mathematical models and
forecasting techniques and set a
precedent for the future of scenario planning.
10
In
the 1970s, this methodology was adapted by Pierre
Wack’s newly formed Planning Scenario team at
the Royal Dutch Shell Group for use in a corporate
setting, primarily to anticipate developments in the
volatile oil and gas markets. ‘Shell’ scenarios were
notable for their trend risk analysis and strategic
planning purposes, and followed seven broad steps
11
:
1
Decide drivers for change/assumptions
2
Bring drivers together into a viable framework
3
Produce seven to nine initial mini scenarios
4
Narrow down two to three scenarios
5
Draft the scenarios
6
Identify the issues arising
The value of Shell’s futuristic
approach was rst realised in the
1973 Arab–Israeli (Yom Kippur)
War, when the rst oil embargo
caught most companies by surprise.
Shell had considered and strategized
for the implications of an oil price
shock, and thus overcame the worst
shocks, and emerged from the crisis
as the sector leader.
Image 1: Herman Kahn of RAND Corporation
(National Archives, 1963)
8. (Kahn 1961) 9. (Amer, Daim, and Jetter 2013)
10. (Durance and Godet 2010) 11. (Jeerson 2012)
10
Scenario Best Practices: Developing Scenarios for the Insurance Industry
to identify events which might “shock” the system and
have a valuable role in tactical planning. The impact of
such scenarios is likely to be acute, rather than accruing
slowly as in the case of trend risks, and they are more
commonly hedged by conventional insurance products.
The impacts associated with a shock event will demand
an immediate response from the insurance community.
The focus of this report is on shock risk scenarios, which
have a wider variety of typologies and methodologies
specic to the insurance industry. The dialogue within
the report is written from a stress test perspective yet is
often applicable in trend risk discourses.
Although stress test scenarios in the form of shocks have
been used by the insurance industry for decades, their
use via modelled catastrophe theory was precipitated
in the insurance industry following Hurricane Andrew
in 1992. At the time, Hurricane Andrew was the most
expensive insured event recorded, and triggered over $16
billion in losses.
12
The nancial impacts caused eleven
insurers to go out of business in the state of Florida and
caused heavy strain on the global insurance community.
13
In the following years, the insurance focused credit
agency, A.M. Best, required American insurers to report
their modelled losses. Lloyd’s of London similarly
introduced their realistic disaster scenarios (RDS)
in 1995 (see Section 5 for an example RDS, Business
Blackout, used as a model case study for scenario
development). The intention of these scenarios was to
provide a communal exercise for insurance organisations
to stress their portfolios and identify any potential
weaknesses which do not meet regulatory thresholds.
The application of stress tests quickly evolved beyond
regulatory purposes and has become a valuable tool in
risk exploration and response planning.
Exploratory Versus Normative
An important distinction concerns the purpose of
scenario development. Scenarios range on a continuum
between exploratory, with the purpose of educating and
expanding awareness of plausible futures, to normative,
with a primary aim to facilitate decision making. Often,
the goal is to concurrently balance exploratory and
decision-based functions.
Exploratory eorts ask, ‘what if?’, as a helpful way to
create a ‘future memory’.
14
This approach explores a wide
and contrasting range of potentially plausible futures
as a function of diverging assumptions (in other words
questioning ‘what would happen if this happens?’), with
the aim of widening the scope of options considered by
users and stimulating imagination and creative thinking
about the future. The focus here is on learning about the
process under analysis, raising awareness, developing
a descriptive assessment of plausible futures, and
taking a specied issue or environment as the subject of
analysis.
15
Exploratory scenarios often apply a forecasting
approach, dening scenarios on the basis of a set of
imposed rules dened from the base year onwards.
16
In contrast, normative scenarios primarily ask, ‘what
for?’. To utilise such a scenario for decision making,
a more narrowly dened set of criteria and objectives
must be explicitly dened.
17
A normative approach
typically uses scenarios that are formulated in technical,
quantitative terms (and thus have less emphasis on
narrative) so that the paths to desirable, or undesirable,
futures can be analysed. The intention is to evaluate
the impact of a set of variants concerning specic
interventions (behaviours and decisions) relative to a
baseline, based on some form of valuation.
18
Such eorts
tend to focus on delivering a product, in the form of a
specic alternative to address a problem, or an advising
tool for evaluating alternatives.
19
A normative approach
can be more easily combined with a backcasting
approach (as opposed to forecasting), dening scenario
pathways only after rst describing the end-points and
reasons back from these end-points, and exploring short-
term decisions to make these changes happen.
20
12. (Grant 2015) 13. (Grant 2015) 14. (Tourki, Keisler, and Linkov 2013)
15. (Riddell et al. 2018; Tourki, Keisler, and Linkov 2013) 16. (Van Vuuren et al. 2012)
17. (Birkmann et al. 2015) 18. (Henrichs et al. 2010; Tourki, Keisler, and Linkov 2013)
19. (Tourki, Keisler, and Linkov 2013) 20. (Robinson 1990; Dreborg 1996)
11
Cambridge Centre for Risk Studies
Participatory Versus Expert-Driven
Another divergence in scenario design concerns who
‘owns’ the process, with a key distinction made between
top-down, expert-driven (or ‘analytical’) approaches
and bottom-up, participatory approaches. Both have
advantages and disadvantages, and each may serve
dierent purposes, although they are not necessarily
discrete, with eective scenarios often including
elements of both. We emphasise the importance
of participation in the scenario process, since this
dimension is often undervalued or excluded in insurance
applications of scenarios.
Expert-driven approaches have the objective of providing
rigorous descriptions of plausible futures, including
details that are well supported by available science.
21
Such approaches are oriented towards decision makers,
and as a result tend to neglect other stakeholders. They
are analytical in approach and allow for exploration
of large-scale phenomena, for example global climate
change, which may pose logistical diculties to
participatory approaches.
In a participatory approach, scenario developers
work together with stakeholders, namely the people
potentially aected by scenario outcomes, rather than
delivering scenarios as a top-down means of education.
Participation targets and integrates stakeholder needs
and values, and while scientic and technical knowledge
remains important, such approaches makes use of
cultural perspectives, knowledge, and experience beyond
the involved experts to dissect complex issues. No group
knows everything, and each will learn from others
through the scenarios, providing everyone is represented
in the discussion. Eective communication of scenario
information is much easier than accurate communication
of technical information (such as probabilistic risk). Such
diverse engagement is eective in developing community
understanding and investment in decision making,
builds trust, and encourages broader acceptance of the
ultimate scenario outcomes.
22
Participatory approaches
enable scenario developers to understand, examine, and
discuss the links between phenomena at dierent scales
– for example how global or sub-national trends relate to
the vulnerability in specic regions or municipalities.
23
Scientic and technological developments have driven an
increasing role of technology and expertise in scenario
approaches but demands for improved participation and
accountability; and criticism of technical expertise, have
also grown. Within the insurance industry scenarios
are generally expert-driven, although there has been a
recent eort to better involve stakeholders. Examples
include community partnerships and local risk planning
initiatives, or the rise of social impact bonds.
24
Further distinctions can be made, aligning with
exploratory or normative, and participatory or expert-
driven approaches, as follows:
Intuitive versus formal processes
Process design refers to how scenarios are developed,
or their methodological aspects, ranging from
intuitive to formal approaches. Intuitive processes
focus on qualitative knowledge and are participatory,
incorporating many perspectives from a wide range of
backgrounds and knowledge bases.
25
In contrast, formal
processes regard scenario development as an analytical
and systematic exercise, and so depend on quantitative
inputs to build conceptual or computational models.
They are exclusive in the way they only incorporate views
from specic stakeholders or areas of expertise.
26
Process versus product orientation
The scenario development process can be at least as
important for the user as the product, for example if
a scenario is intended to support a specic decision.
A process-oriented scenario includes the user in
development, so that they may learn from the experience
and feedback to enhance scenario ecacy. However,
in many contexts, scenarios are instead communicated
in a linear process, with an end product deliverable
such as a report and or a quantication of loss. In this
case the product is typically more important than the
process, with the potential advantage of reaching a target
audience beyond those participating in the process. If
this is the case, quality, transparency, and legitimacy
need to be emphasised in order to ensure scenarios are
relevant to the user community and can be readily used
for planning and decision making.
27
Qualitative versus quantitative
The distinction between qualitative and quantitative
information is clear in scenario development, but the
contrasting methods may be, and perhaps should
be, combined. Qualitative information, specically
narratives, provide logic to scenario assumptions and
help to dene plausible future developments in situations
where formal modelling is not possible. They provide
an eective way to derive information at dierent scales
or for dierent topics (for example regional scenarios
nested within global narratives). Quantication, via
modelling, adds scientic rigour to scenarios, expanding
on numerical estimates of futures developments (often
based on simulation tools) where relevant and reliable
information is available. Quantitative outputs can
strengthen communication through clear denitions
and rules.
28
21. (Star et al. 2016) 22. (Star et al. 2016) 23. (Birkmann et al. 2015)
24. For more information on social impact bonds see (Social Finance Inc. 2012)
25. (Van Notten et al. 2003; Tourki, Keisler, and Linkov 2013)
26. (Tourki, Keisler, and Linkov 2013) 27. (Van Vuuren et al. 2012) 28. (Henrichs et al. 2010)
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Scenario Best Practices: Developing Scenarios for the Insurance Industry
Deterministic Versus Probabilistic
Scenarios are also characterised as either deterministic
or probabilistic. A deterministic scenario is created by
selecting a specic set of parameters and conditions,
while a probabilistic scenario considers a multiplicity of
outcomes, each with its own probability of occurrence,
depending on the probability distribution of the input
parameters and conditions.
29
A deterministic scenario
treats the probability of occurrence as nite, whereas
probabilistic modelling is intended to address the
uncertainty with a ‘complete’ probability distribution of
synthesised events.
Deterministic scenarios are recognisable by their focus
on the causal chain of circumstances that will give rise
to unusual or extreme outcomes. They are an eective
means of exploring phenomena speculatively or
hypothetically when they are not very well understood
or there is a high degree of uncertainty. They can also be
very valuable for exploring emerging risks, specically
where market or policy responses are uncertain.
In comparison, production of a probabilistic scenario is
possible when the underlying process is well understood,
and the causal parameters can be characterised with
estimates of their occurrence rates and distribution.
Each step in the causal chain has a dened distribution
of outcome likelihoods, and the model stochastically
samples from this distribution in many simulations. The
probability of an outcome and its uncertainty structure
is very sensitive to the assumptions made for the input
parameters.
30
By incorporating random variations into
the model, stochastic outcomes show a range of scenario
outcomes, and the likelihood of these permutations.
Techniques for probabilistic modelling are well
understood and documented, and are used in analysis,
such as natural catastrophe modelling, where the
subject phenomena have been comprehensively studied
and for which it is possible to estimate the uncertainty
distributions of the underlying variables.
There is overlap in deterministic and probabilistic
scenarios. For example, probabilistic modelling
can be used to generate a deterministic scenario,
typically such as the worst, best, or most likely case
events. Caution should be taken when comparing
the two types, as probabilistic scenarios still contain
deterministic attributes. Specically, probabilistic
scenarios require all potential outcomes to be dened,
yet in practice the universe is not a closed system.
There are outcomes of future probabilistic scenarios
which cannot be recognised at present; thus, it is not
possible to achieve a perfect probability estimation. Both
deterministic and probabilistic scenarios are used by the
insurance community.
Probability theory is critical in the industry, where
the likelihood of future events is required to develop
a policy or price a premium. This is true even where
signicant uncertainty exists, and it is in this case where
deterministic scenarios can be particularly important
to address uncertainty, providing reference points on
a journey towards probability. It is also important to
note that probabilistic scenarios are only useful when
understood, and where decision makers are not familiar
with the theory, it may be unhelpful or even misleading.
For example, return periods, or recurrence intervals,
are standard calculations for describing the magnitude
of potential events – such as a 1-in-100-year ood – but
are prone to misconceptions and misuses that are well
acknowledged but still widespread.
31
In cases where
communicating scenarios to non-experts is required, it
may be that probability should not be depended on, and
a deterministic approach could have greater value.
29. (Renard, Alcolea, and Ginsbourger 2013) 30. (Lorenz 1963) 31. (Serinaldi 2015)
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14
Scenario Best Practices: Developing Scenarios for the Insurance Industry
3. Using Scenarios in the Insurance Industry
This section documents the various roles that scenarios play within the insurance industry and
explores who is using, or could better use, scenarios. The application of scenarios can be broadly
categorised into universal uses of scenarios, and those specic to the insurance industry.
3.1 General Scenario Uses
The action of developing a scenario carries a series of benets, some of which are simply a consequence of
the scenario building process. We highlight a series of outcomes that were often cited by insurance industry
representatives whose comments informed the development of this report, and were notably consistent,
regardless of a scenario’s intended use or application. These are individually discussed below.
Supporting Decision Making
Scenarios can be highly eective tools in support of
decision making, oering a creative and structured
mechanism to test and validate decisions in a scenario
planning process. When managers make decisions about
the future, concerning either near-term operations or long-
term strategy, they cannot only expect positive outlooks,
and must also be proactive in preparing for negative
events. This proactive outlook is a key characteristic of
enterprise risk management, contrasting with the typically
reactive approach of traditional risk management.
Scenarios facilitate discussion on how risks can be planned
for and be managed or mitigated eectively with robust
decisions and strategies. Further, decision makers must
factor in the associated risks on the belief of a certain set of
assumptions, the validity of which scenarios test.
Aiding Communication
Scenarios routinely function as a communication tool in
the industry, facilitating the sharing of ideas, risks, or
responses. Communication may occur formally during
the distribution process, or more informally during
the development and research phase. Scenarios are
especially valuable when discussing abstract ideas, or
complex risks, as they provide examples and context
to the issue, ensuring a consistent interpretation and
understanding. Furthermore, by providing a well-crafted
scenario which is mutually accessible to multiple parties,
consumers of the scenario have an equal platform
for communication across dierent sectors or areas
of expertise.
Demonstrating Due Diligence
The insurance industry is required to practice due
diligence to keep themselves and their insureds safe.
One component of due diligence is recognising what
risks exist, and where vulnerabilities exist within the
organisation. Scenarios assist in achieving this due
diligence, as they provide a systemic and comparable
platform for examining these risks, and a sheltered
sandbox to identify and test potential vulnerabilities.
These exercises can aid in answering questions such
as what silent exposure may exist, or if there is clash
potential on existing policies. By addressing areas
of uncertainty and taking informed risks, insurers
can demonstrate that potential consequences have
been considered and reasonable precautions have
been taken.
Identifying Bias
Scenarios provide a platform to explore hypothetical
outcomes and identify potential (dis)inclinations or
partialities that organisations have towards certain
situations and decisions. Taking a broad set of
scenarios mitigates well known behavioural eects like
conrmation and availability biases. Such an approach
also allows for alternative responses to be compared
to a baseline. By setting these processes up in advance,
insurers can be mindful of these issues and take
proactive measures to ensure that the decision-making
process remains objective. This yields a systemic benet
that is realised over time.
15
Cambridge Centre for Risk Studies
Scenarios to Support Robust Decision Making
Deep Uncertainty
Deep uncertainty exists when decision makers do
not know, or cannot agree on, a system in question
and its boundaries, the probabilities of model inputs,
or the consequences of interest and their relative
importance.
32
Such uncertainties persist for many drivers of global
change, including environmental, economic, or
technological developments. Societal perspectives
and preferences also change over time, including
stakeholders’ interests and their evaluation of
plans. As the future unfolds, plans are adapted to
developments, so decisions are part of the storyline
and an essential component of uncertainty.
33
Innovative analytical approaches
34
of ‘decision
making under deep uncertainty’ are emerging to
cope with uncertainty, and to help decision makers
evaluate robust and adaptive management strategies.
They help to build a consensus between stakeholders
with dierent values, priorities, and solutions, who
can agree on a decision for very dierent reasons.
35
The process reveals future threats, as well as
opportunities, confronting each plan. This paradigm
relies on exploratory modelling, typically involving
scenario approaches that harness speculation and
imagination to consider ‘unknown unknowns’.
36
Robust Decision Making
Robust decision making (RDM)
37
is one example of
a dened approach for analysing deep uncertainty,
which uses iterative, model-based scenario analysis.
The RDM methodology helps decision makers to
identify and improve robust strategies by testing
them against a very large exploratory scenario set
(of hundreds of possible futures) to reveal their
strengths and limitations. Statistical analyses of
model iterations identify the key conditions under
which strategies fail to satisfy their objectives. RDM
also has a participatory component, with stakeholder
deliberation used to dene (un)desirable outcomes,
and to rule out implausible scenarios.
38
Robust strategies will satisfy decision makers’
objectives in many scenarios, rather than being
optimal in any single future.
39
In other words, they
are ‘good enough’, rather than optimal options,
aiming to minimise regret rather than maximise
expected utility. RDM also helps to compare
strategies along other dimensions such as cost,
feasibility, and social acceptability.
40
RDM has been widely applied to explore where
deep uncertainty exists, including in the domains of
climate change
41
, risk and resource management
42
,
and insurance specic applications, for example the
feasibility of terrorism insurance
43
. An important
consideration of RDM is that it requires large
amounts of quantitative information and a high
degree of expert knowledge.
32.(Kwakkel, Walker, and Haasnoot 2016; Hallegatte et al. 2012) 33.(Haasnoot et al. 2013) 34.See (Haasnoot et al. 2013; Kwakkel, Walker, and
Haasnoot 2016) for discussions of various approaches to support decision making under deep uncertainty 35.(Tuck 2016) 36.(Olabisi 2017)
37.See (RAND Corporation 2019) for detailed use cases 38.(Olabisi 2017) 39.(Rozenberg et al. 2017) 40.(Rozenberg et al. 2017; Lempert et al.
2013) 41.(Lempert, Popper, and Bankes 2003; Lempert and Kalra 2011) 42.e.g. (Sayers, Galloway, and Hall 2012; Beven and Alcock 2012; Popper
et al. 2009) 43.(Lempert et al. 2013) 44.(Roxburgh 2009)
Sensitivity Analysis
Insurers are required to make assumptions and
estimates daily, considering many dierent variables and
evaluating their potential interaction with one another,
towards making a cost-benet analysis. Scenarios can
assist in this process, as they allow users a sheltered
environment to explore uncertainties and investigate
alternative futures which may arise, incorporating a
greater appreciation of the direct and indirect impacts of
their decision choices today.
Addressing Uncertainty
Scenarios expand understanding of a range of plausible
outcomes, each supported by a dening sequence of
events. Humans inherently expect that change will
occur gradually and that the future will reect the
past. By generating deeper insight into the underlying
drivers of change, scenarios may demonstrate how
and why changes could develop quickly and otherwise
unexpectedly, and which drivers do or do not have the
ability to cause consequential change.
44
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Scenario Best Practices: Developing Scenarios for the Insurance Industry
Systems Thinking
The capability to capture interconnectivities between
complex systems, or ‘system of systems’, is critical
to scenario planning. Systems thinking is a holistic
approach to address complex interconnections and causal
relationships, rather than on snapshots and independent
aspects, of a problem. Given the abundance of resources
on this topic, only a brief overview is provided here, with
an emphasis on the importance of wholly understanding
systems when using scenarios. The approach exposes
that which is not immediately obvious, providing a lens
to detect underlying controlling forces and relationships
between individual components, to understand the entirety
of a system. The iceberg analogy
45
(Figure 3) is a useful
way to illustrate systems thinking and enable practitioners
to appreciate the deeper perspective. As humans, we
typically notice events in the world around us (the ‘tip’ of
the iceberg) in a reactive and counteractive mode, only
seeing a small part of the underlying dynamics. Only when
we look below the (water) surface for patterns of behaviour
can the event be better understood with scenarios that
explore how interconnectivities may control the future.
Delving further into understanding these dynamics at a
structural level enables exploration of the structural level
of various risks facing an organisation.
46
3.2 Insurance Use Cases of Scenarios
In addition to the generic benets that scenarios provide
during the development and decision-making process,
scenarios have specic and unique benets to the variety
of users within the insurance industry (Table 1). This
report proposes that the insurance applications can
be categorised into four use cases. These uses overlap
and share common traits and should be recognised
as interconnected components. These use categories
are summarised in Table 2, and are described on the
next page.
(Enterprise) Risk Managers Regulators
Accumulation Controllers Claims Managers
Underwriters Risk Capital Controllers
Pricing Actuaries Business Planners
Advisors Investment Manager
Transaction Intermediaries Product Designers
Table 1: Example scenario users within the insurance industry
Use Category Description Example Uses Trend Shock
Understanding Tail Risk Identify extreme, low probability risks Reinsurance purchasing,
counterfactualanalysis
Understanding
EmergingRisk
Identify new and undened risks and
policies
Understanding policy wording, trialling a
concept, problem verication
Strategic Planning Identify risks and opportunities for
anorganisation
Short-term and long-term planning,
particularly with regard to strategic
response to opportunities or threats
Accumulation Management Identify maximal potential losses and
potential for risks to scale
Probable maximum loss (PML)
identication, clashscenarios
Table 2: Uses of scenarios within the insurance industry
Figure 3: Systems thinking – the iceberg analogy
(adapted from Senge, 1990; Van der Merwe, 2008)
Events
Patterns of Behaviour
Structure of
the system
Casual relationships,
driving forces,
assumptions
Increasing ability to inuence and learn
45. (Kauman 1980) 46. (Van der Merwe 2008)
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Cambridge Centre for Risk Studies
Understanding Tail Risk
Within the insurance industry, a tail risk refers to an
extreme and highly unlikely event which has signicant and
often immediate consequences. The term ’tail’ originates
from statistics – for example, if outcomes are distributed
according to a standard bell curve (normal distribution),
then outcomes that are more than three standard deviations
below or above the expected outcome (the mean) only occur
in 0.3% of cases – these are the tails of the distribution.
These extremes, with either positive or negative impacts,
are, by denition, highly improbable and dicult to predict.
Within the insurance industry, the focus is typically on
the severe negative impacts that result in losses, although
recognising the improbable positive outcomes also are
of interest. As the exercise is hypothetical, variables can
be adapted and controlled to explore dierent potential
outcomes and their consequences. These scenarios assist in
answering the hypothetical question “what if?” and provide
a reference point to build from. As events unfold and the
probability distribution of a risk evolves, the denition of a
tail risk may also change.
Understanding Emerging Risks
An emerging risk is a new risk, changing risk, or novel
combination of risks for which the broad impacts, costs and
optimal management strategies are not yet well understood.
Emerging risks are driving an increase in insurance
exposure. Emerging risks oer opportunities for new
products in the market but are also a potential threat to
capital adequacy. Understanding the breadth of the risk and
its potential consequences can allow insurers to embrace
emerging risks and limit unintended exposure. Scenarios
are a tool in exploring these risks, as they provide a
platform to develop hypothetical events and consequences.
As emerging risks are fundamentally uncertain, scenarios
allow exploration of hypothetical events through which
these uncertainties can be stressed. This provides a gauge
of the potential hazard severity or scale, and what limits or
precautions should be taken at the time. When a specic
outcome has not occurred in reality, scenarios can be used
to see what pay-outs may be triggered, and how dierent
policies may be interrupted should such a risk emerge.
Strategic Planning
Strategic planning is the process by which an organisation
denes its strategy for the future, with consideration of
trend risks which have the potential to threaten strategic
goals. This can range from determining resources and areas
of investment, to setting priorities and targets. Specically,
scenarios are often used as they allow users to identify and
adjust factors which may impact these goals. Scenarios can
be used to project what may occur in the short- and long-
terms if conditions remain consistent, but also estimate
how the future might vary with various internal and
external inuences. Scenarios fundamentally support the
needs of communication across dierent stakeholders and
areas of expertise and provide a communal platform for
discussion and problem solving. When considering strategic
planning, members of an organisation can contribute to
scenario building, creating a holistic planning process.
While, as previously discussed, trend risks are typically
not insured via the current range of insurance products,
insurers are increasingly being called on to address
trend risks. Therefore, strategic planning should not
only be considered as relevant to an insurer’s internal
risk management, but also as an opportunity for insurers
to address trend risks that threaten the strategies of
organisations that serve the industry with business.
18
Scenario Best Practices: Developing Scenarios for the Insurance Industry
Cyber Terrorism: AnEmerging Risk
Cyber terrorism has remained one of the most
notable emerging risks within the insurance industry
and continues to build its reputation as a potential
cyber insurance game-changer. Cyber terrorism
is dened by the Federal Bureau of Investigations
as: ‘any remediated, politically motivated attack
against information, computer systems or computer
programs, and data which results in violence against
non-combatant targets by sub-national groups or
clandestine agents’.
47
Cyber security professionals, governments, and law
enforcement are becoming increasingly concerned
with the potential for traditional terrorism groups
to exploit the cyber landscape to cause physical
destruction and human injury.
48
Insurers have
been reluctant to oer coverage for cyber terrorism
in their insurance products due to signicant
uncertainties surrounding the probability and
severity of cyber terrorism events. In a recent review
of 26 cyber armative policies, only 12% of cyber
insurance products oered terrorism coverage
in 2016.
49
The ambiguity around the process of
attribution of cyber attacks to terrorist actors has
also compounded this uncertainty.
50
Scenarios have played a key role in the developing
the market for cyber terrorism coverage by
quantifying the potential exposure (particularly silent
exposure) insurers could face when a cyber terrorist
event occurs. Research commissioned by Pool Re, the
UK’s mutual terrorism reinsurance pool with the UK
Government, highlighted realistic cyber terrorism
scenarios that could result in signicant physical
damage and thus trigger silent exposure in property
lines. In response to the identication and estimated
quantication of this cyber terrorism insurance
gap, Pool Re have expanded their terrorism product
coverage to include explicit cover for property
damage and the resulting business interruption
caused by cyber terrorism.
51
Accumulation Management
Accumulation management, also described as
aggregation risk management, considers what risks exist
within a portfolio of insurance policies for large numbers
of claims to arise from the same underlying cause or
event. Scenarios of the events that could cause large
numbers of simultaneous, correlated losses identify the
potential systemic attributes that policy holders might
share. This allows insurers to test the loss potential for
their specic portfolio to those extreme losses. They also
enable the exploration of hypotheses of how the risk
might scale or increase in magnitude if a variable were
to change. By estimating how large an event might be
and how likely it is to occur, an insurer can eectively
protect their exposure through limits and exclusions. A
use of the scenario might be to help insurers design their
terms and conditions, product design, and the limits and
deductibles they might oer to protect themselves from
taking large systemic losses.
Similarly, in identifying what the maximum loss for
insurers might be, exposure limits can be introduced to
limit what is insured, or what inclusions and exclusions
are considered. This type of scenario is referred to as the
Probable Maximum Loss (PML) and is often required
when deciding a risk appetite or tolerance of loss for a
line of insurance business and can be used to regulate
the amount of new business that is underwritten in
the future.
Scenarios play a valuable role when discussing
accumulation and maximum loss, as they provide a trial
ground to explore what types of events would cause
broad impacts, especially across multiple portfolios,
or classes of insurance. They are also helpful when
considering limits and exclusions, as insurers can trial
what amount of risk they feel comfortable accepting, in a
controlled environment.
47. (Alford 2017) 48. (Broadhurst et al. 2017)
49. (Risk Management Solutions Inc, in collaboration with Cambridge Centre for Risk Studies 2016)
50. (Evan et al. 2017) 51. (Insurance Journal 2018)
19
Cambridge Centre for Risk Studies
3.3 Allocating Risk Capital
Capital modelling is used when deciding how much
capital should be priced and reserved to cover potential
risks.
52
The role of capital allocation modelling in the
insurance industry is typically focused on ensuring
capital requirements for regulatory purposes are met,
without signicantly impacting daily underwriting
decisions.
53
This is a method known as ‘Regulatory Risk
Based Capital’. Under Solvency II pillar one, insurers are
obligated to meet the Minimum Capital Requirement and
Solvency Capital Requirement.
54
To meet these requirements, insurers can either use
a ‘one size ts all’ prescriptive model provided by the
regulator, which uses a standard formula, or else develop
an internal capital model (ICM).
55
The use of partial or
fully internal capital models goes beyond the scope of
regulatory compliance by providing greater insight into
a company’s risk prole and is essential for navigating
towards ecient capital allocation.
56
To validate a modelling process of capital allocation,
insurers often develop scenarios to assess the resilience
of these capital reserves to shock and trend risks.
Scenario modelling is used to validate insurers decisions
on the allocation of capital across lines of insurance by
estimating their exposure to a disaster scenario.
Using clash aggregation modelling techniques, insurers
can test their capital allocation reserves based on
a disaster scenario that impacts multiple lines of
insurance. Clash modelling allows insurers to better
understand their potential losses across multiple
lines of business and develops a narrative for capital
requirements necessary to cover these losses.
Solvency II
In 2009, the European Union Insurance and
Occupational Pensions Authority (EIOPA),
57
a
nancial regulator body of the European Union,
introduced the EU Solvency II Directive. The
directive aims to homogenise EU insurance
regulation and focuses on an enterprise risk
management approach towards required capital
standards.
58
Solvency II is primarily concerned with
the level of capital reserves insurance companies
should hold to reduce the risks of insolvency.
59
This
legalisation was driven by the events of 2008, when
the Financial Crisis and subsequent Great recession
highlighted the necessity for insurance companies to
manage their capital allocation to remain solvent. To
ensure the solvency of EU insurance companies, the
Solvency II program has three main areas, known
as ‘pillars’:
Pillar 1: Financial Requirements
Pillar 2: Governance and supervision
Pillar 3: Reporting and Disclosure
Pillar 1, known as the ‘quantitative pillar’, puts
demands on the required economic capital that
insurance companies must hold.
60
The pillar
stipulates two thresholds that insurance companies
must adhere too: Solvency Capital Requirement
(SCR) and Minimum Capital Requirement (MCR).
The SCR requires insurers to estimate the level of
capital needed to meet quantiable risks on their
existing portfolios, including one year’s expected
new business.
61
MCR is the lower bound of the SCR
and is the level of capital in which regulators would
consider the insurer to be in signicant danger of
insolvency. The MCR is calibrated in the Solvency II
regulations as 85% value-at-risk over one year from
valuation date.
62
Pillar 2 is known as the ‘qualitative pillar’ which
sets out clear requirements regarding how the
quantitative objectives of pillar 1 should be achieved.
The pillar requires companies to design eective
systems of governance which are proportionate to
the nature, complexity and scale of operations.
63
An
insurer must have written internal policies in relation
to risk management systems and internal controls of
the organisation. Under the Own Risk and Solvency
Assessment (ORSA) area Solvency II, insurers must
action a signicant self-assessment of the risk they
are exposed to in the short and medium run.
64
ORSA
aims to go beyond the modelling requirements in
pillar 1 and for the insurer to think about additional
risks the insurer may be exposed to.
Pillar 3 outlines the reporting requirements of
company’s risk with respect to which information
should be disclosed such as risk exposure and
concentration, and the frequency with which this
information should be reported.
65
52.(Cummins 2000) 53.(GIRO Working Party 2016) 54.(Vandenabeele 2014) 55.(Krvavych 2018) 56.(Boonen 2017)
57.Formerly known as the Committee of European Insurance and Occupational Pensions Supervisors 58.( Vandenabeele 2014)
59.(House of Commons Treasury Committee 2018) 60.(Boonen 2017) 61.(Lloyd’s of London n.d.) 62.(Vandenabeele 2014)
63.(Financial Services Commission 2009) 64.(House of Commons Treasury Committee 2018) 65.(Vandenabeele 2014)
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Scenario Best Practices: Developing Scenarios for the Insurance Industry
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Cambridge Centre for Risk Studies
4. Shock Risk Scenario Development:
InsuranceStress Testing
There are many types of scenarios which have been developed by the insurance industry, for particular
applications and with diering development methods. During the literature review and consultation
process for this report, a wide variety of techniques and development processes were identied
in surveys of insurers and stakeholders. There is no standardised approach, consensus, or single
proto-typical method in use. Instead, there are common features across multiple methodologies.
In this section we focus on the underlying similarities and propose a series of checkpoints to ensure
developed scenarios can be applied widely and meet the needs of the broader insurance community.
4.1 A Checklist for Scenarios
The rst checkpoint in the scenario development
process is identifying who the scenario users are,
and how they hope the scenario will be used in the
future. Within the insurance community there are an
abundance of potential users with individual needs
and criteria for a scenario. The best way to gauge these
needs is by talking with the intended audience or users
and taking the time to understand what they hope a
scenario to achieve. Supporting the direct feedback from
future users, scenario developers should also reect on
the following:
Background Knowledge refers to the existing
familiarity that users have with the subject. This is
an indicator for the type of narrative and level of
description that should be provided. If the scenario
is proposing an event that is novel to the user, the
scenario and its associated documentation should
provide additional resources regarding the current
risk landscape and use additional description when
suggesting cascading impacts. Comparatively, if the
user is very familiar with the proposed risk event, the
scenario can address a dierent level of detail and
specication. The terminology and language used
to describe the risk should also be adapted based
on the familiarity of the end user with the subject
matter. As a standard practice, the scenario should
include enough research and reference material so
that it remains widely accessible, regardless of the key
audience’s familiarity.
User Resource is the amount of time and human capital
that the user can be expected to dedicate to read and
interpret the scenario. The resource allowance should dictate
the length and detail of a scenario. Should the scenario be
intended for a user interested in new and emerging risks
over a long-term period, more resources may be allocated to
reviewing an extensive report and background material. If,
for example, the user is focused on the clash risk of a specic
area, there may be a greater urgency to understand potential
outcomes and losses, and so fewer resources would be
available to review an extensive report.
Existing Guidelines refer to the rules and regulations
that may have been put in place by the user regarding the
scenario’s development and presentation. This is most
commonly seen in the case of regulators and authorising
bodies, who are required to review and compare large
numbers of scenarios in a short period of time. Prior to
the development of the scenario, one should check to
ensure that available guidelines required by the user are
reected. These guidelines might include the types of
scenarios required, the number of variants included, and
the loss estimation process.
Audience refers to how the user intends to share the
material, and whether it will remain as an internal
resource, or be published externally for public use. Public
scenarios will require signicantly more documentation
and reference material than those for internal use, to
mitigate potential ambiguity.
22
Scenario Best Practices: Developing Scenarios for the Insurance Industry
4.2 Scenario Development: a Stress Test Perspective
The next several checkpoints in scenario development
relate to its construction. The intention of the report is to
provide an accessible resource and guide for developing
scenarios, but the process is varied and often attuned
to the specic needs and interests of stakeholders.
Accordingly, the steps discussed below are recommended
checkpoints to consider as a practitioner works through
the scenario process. Users should adapt the methodology
to create scenarios which work best for them, given their
audience, resources, and desired use. Further, while it
outlines a linear step-by-step structure for clarity, we
encourage the scenario process to be an iterative one, in
which stakeholder engagement provides opportunities
for review and revision to ensure it succeeds in fullling
its aims.
A case study of a worked example of scenario development
using this framework is provided in Section 5, based on
the 2015 Lloyd’s Business Blackout Report
66
, originally
developed to address emerging cyber risk within the
insurance industry.
There are various types of scenarios which can be used
within the insurance industry (Section 2.2). This section
focuses specically on stress test scenarios, which are
among the most widely used scenario types and carry the
greatest potential for external agency development. Many
of the recommendations made for stress test scenarios are
broadly applicable to other forms of scenario development.
A stress test is an exercise conducted within the insurance
and nance community to explore an organisation’s limits
and dene the magnitude of event that would ‘stress’ the
institution. This is often measured in terms of nancial
capital, with stress tests imagining extremely expensive
events leading to an inux of insurance claims or nancial
losses. Stress tests often focus on rare and extreme events
(tail risks) which result in a dramatic impact.
Within the insurance industry, stress tests are a common
requirement for external regulation and internal planning
and are a recognised means of evaluating the robustness
of an institution, both currently and in the future. The
process of developing a stress test involves both creating
a hypothetical event and identifying the consequences
that event would have upon the organisation/insurance
sector. This report suggests that the scenario development
process is best considered an iterative progression rather
than a linear trajectory. This is due to ongoing adaptations
and adjustments which are made as a researcher learns
more during the scenario’s development. The process is
summarised in Figure 4. The process can essentially start
at any phase within the process, though most will nd it
logical to rst identify a risk or question. Others may start
by formulating intended scenario outcomes and work
backwards, which is a reverse stress test.
Exploring Knowns and Unknowns
In 2002, the US Secretary of Defense, Donald
Rumsfeld, stated:
“There are known knowns. There are things we
know that we know. There are known unknowns.
That is to say, there are things that we now know
we don’t know. But there are also unknown
unknowns. There are things we do not know we
don’t know.”
67
Although the saying was intended for a national
security perspective, the same intention can be
applied to a broader risk perspective and our
understanding of potential hazards. Rumsfeld
correctly suggested that there are certain
unknowns which we are aware of and can in
turn eectively prepare for. Alternatively, there
are unknown unknowns, or unidentied risks,
which are dicult to imagine or plan for in
advance.
68
Within the insurance community, it
is the unidentied risks which carry the greatest
uncertainty and can have some of the most
consequential nancial impacts. Although risk
management is designed to consider potential
emerging risks, there are some risks for which
management is not possible.
The role of stress test scenarios within the
insurance industry is to identify what type
of extreme events might occur, and what
impacts would result. By shifting away from
what is likely or known and focusing on what
is plausible (either now or in the future), a
broader interpretation of the risk landscape can
begin to emerge. It is unlikely that scenarios
will identify an unknown unknown risk, but
they can encourage organisations to widen
their knowledge of their known unknown
risk environment and reduce the surprise of a
shock event.
When researching the subject, it is also helpful
to identify similar historical incidents, which
can provide precedent for the proposed event.
Alternatively, counterfactual analysis considers
events which might have occurred but didn’t.
Counterfactual analysis can be especially helpful
when considering event outcomes which have
never happened before.
69
By anchoring aspects
of the scenario in existing events, the scenario
maintains it credibility and relevancy.
66. (Cambridge Centre for Risk Studies 2015) 67. (Rumsfeld 2002)
68. (Kim 2012) 69. The Economist 2017)
23
Cambridge Centre for Risk Studies
Step 1: Scope the Risk
This step aims to contextualise the objectives
and resultant decisions of the process. It
is logical to approach the scenario process with the
statement of a problem or research question to be
answered, most simply by dening a specic risk facing
an organisation. For example, within the insurance
industry, a common theme is to better understand
potential or emerging risks and identifying how they may
aect the insurer’s portfolio. A research question typically
starts broadly (e.g. ‘what are my silent cyber exposures?’)
and evolves to a more specic question during
development (e.g. ‘what are my silent cyber exposures to
an industrial explosion event?’). The problem or question
will be rened throughout the research and development
process. Stress test scenarios are particularly helpful
when identifying exposure to unlikely but extreme events.
Although these events are dicult to assign a probability,
extreme scenarios are still valuable in investigating
interconnectivities and indirect impacts.
Where the risk is uncertain or unknown, the research
question should instead aim to dene the issues or
vulnerabilities that the scenario exercise aims to expose.
In this case, the desired outcome of the scenario process
is likely to identify one or more risks to an organisation.
A reverse stress test is an alternative way of framing a
question or problem, instead focused on the hypothetical
point of failure that would cause an organisation to
become unviable. The scenario then forces users to
identify the vulnerabilities which exist and might
cause such an eect. Reverse stress tests are helpful in
highlighting the potential for failure and addressing any
false sense of security concerning the robustness of a
business and its resilience to a shock.
Step 2: Conduct Background Research
Background research should include
consultation of the relevant sources of
knowledge, including the academic literature for a
scientic understanding of the topic, as well as the
knowledge of insurance industry experts and associated
stakeholders within and beyond the sector. Each
dimension of risk should be considered: the hazards,
whether acute, shock events, or slow-onset, trend
phenomena; exposure of an organisation, sector,
market to a hazard; and vulnerabilities at each of
these levels that have the potential to drive loss. A
distinction should be made between idiosyncratic risks
that aect a single organisation, and systemic risks
that drive a major collapse in a specic sector or the
broader macroeconomy.
Various stakeholders in the insurance community are
often willing to help at this stage and can provide nuanced
advice specic to certain risks. Speaking with subject
area experts outside the insurance industry can provide a
balanced perspective, as they have dierent perceptions
of risks, vulnerabilities, or potential impacts. Establishing
both an internal and external perspective is valuable
for this reason. This process alone may be valuable in
widening the view of known unknowns, highlighting risks
that do not yet feature on an organisation’s radar.
Step 4
Step 5
Develop
Candidate Scenarios
Develop
a Narrative
Figure 4: Outline of the scenario development framework for the insurance industry
Step 1
Step 8
Step 3
Step 6
Step 2
Step 7
Scope
the Risk
Evaluate
and Update
Frame the
Scenario(s)
Assess Impacts
and Materiality
Conduct
Background Research
Communicate
and Act
24
Scenario Best Practices: Developing Scenarios for the Insurance Industry
Step 3: Frame the Scenario(s)
Here, framing the analysis refers to
consideration and denition of the key aims,
benets, and characteristics of the scenario process. It is
the process of determining what type of scenario is most
appropriate for the current use case.
As discussed, to be eective, scenarios should blend
approaches and typologies to t their purpose. Figure 5
intends to guide this framing with a series of questions
that aim to provoke consideration of key practical
decisions in the process:
Aid Communication Demonstrate Due Diligence Identify Bias Sensitivity Analysis Addressing Uncertainty
To contextualise complex
risks and promote
stakeholder understanding
To assess risk exposures
and understand their
nancial implications
To explore partialities
that stakeholders may hold
towards certain decisions
To investigate the power
and variance of controlling
variables on a risk
To expand understanding
of the range of
plausible outcomes
Trend Risk Scenario Shock Risk Scenario
Slow-onset, trend phenomena
that emerge gradually over time
Sudden-onset, shock events
that occur quickly or unexpectedly
Exploratory - To ask ‘what if?’ Normative - To ask ‘what for?’
To stimulate imaginative thinking about the future
and widen understanding of available options
To better understand the path to desirable futures
and evaluate the impact of decisions
Figure 5: Framing a scenario – scenario typologies and applications
What is the scenario for?
How can the scenario benet stakeholders?
On what timescale does the risk materialise?
Which is the more important scenario outcome?
Who owns and contributes to the scenario process?
Understanding Tail Risks Understanding Emerging Risks Strategic Planning Accumulation Management
To identify and understand extreme,
low probability risks
To imagine and comprehend
new or evolving risks
To dene a resilient strategy
for the future that alleviates risks
To explore possible extreme or maximal
correlated losses to insurance portfolios
Participatory - Bottom-up, co-production of knowledge Expert-Driven - Top-down, analytical
To incorporate stakeholder culture, knowledge,
and experience in the process and end product
To deliver rigorous scientic descriptions
of plausible futures to decision makers
Probabilistic Deterministic
To estimate the likelihood of occurrence
based on the variance of quantied causal parameters
To speculatively explore phenomena
that involve a high degree of uncertainty
Is the scenario required to dene the likelihood of an outcome?
25
Cambridge Centre for Risk Studies
Step 4: Develop Candidate Scenarios
Developing candidate scenarios typically
occurs in tandem with the research process and
involves imagining the distinct features and narratives of
potential scenarios. This should be a free-thinking exercise
and includes exploring threat types and characteristics,
key variables and controlling factors, as well as expected
consequences and impacts. Informed by the background
research, a list of candidate scenarios should be formalised.
It is helpful at this stage to make the candidate list as
extensive as possible. Developers should consider the key
question or problems during this process and attempt
to list scenarios that satisfy the required criteria, while
ensuring they remain plausible and true to the reality as
understood from the background research. For each of the
candidate scenarios, consider what risks are measured, and
what types of consequences they may lead to. Once a series
of potential scenarios have been listed, they will be ranked
and selected for further development.
There are several methods to rank and select scenarios,
which are largely based on user preference and a scenario’s
intended application. Two common approaches include the
use of an impact uncertainty matrix, and the uncertainty
breadth approach. In the impact-uncertainty matrix (Figure
6), outcomes are projected upon a matrix which gages both
impact and uncertainty. Scenarios which have high impact
and high uncertainty are thought to benet the greatest
from further research. This is followed by scenarios which
have either a high impact or high uncertainty. Those which
are certain and unimpactful are deemed least appropriate.
The uncertainty breadth approach is an alternative method
which selects scenarios that cover the greatest range of
outcomes. In this case, multiple scenario variants would
be selected that are the most dierent from each other and
had the least amount of overlap. The uncertainty breadth
approach is especially valuable for emerging risks which
typically have more unknowns.
Determining a severity
It can be helpful to estimate what the frequency and severity
of the loss may be to a rough rst order. This process
identies extreme yet plausible events and can provide
some context to the discussion. Insurers often discuss size
and severities in terms of ‘return periods’, or the estimated
time interval between the occurrence of similar events.
For example, a 100-year return period event implies a
severity level that only has a 1% chance of occurrence in a
given year.
70
When determining the event severity, it is also helpful to
consider the size and scale of the (1) trigger event, and the
(2) market response. Often what generates a stress event
is a cascading set of incidents which amplify the triggering
incident. In this perspective, the trigger event may be
common, yet the response may be very uncommon, which
results in an overall extreme and unusual event. In most
cases, it is advised to not make the scenario too extreme,
as ‘game-over’ severities are not actionable. Although
there will be scenarios which can be much more severe or
stressing, events which result in the failure of society or
destruction of an industry as a whole, are often not relevant
for traditional stress test users. This is because, in such
cases, the insurance industry would be unable to support
such colossal losses. Scenarios should be kept potentially
plausible and broadly recoverable.
Step 5: Develop a Narrative
A detailed narrative expands the scenario
description to provide the required detail on
which to build the analysis. The narrative should include
a variety of dimensions of a future event, including
context, triggers, timelines, geography, responses,
and implications. When determining these factors,
it is helpful to once again refer to the intent of the
exercise expressed when scoping the scenario (Step 1).
Geography, timelines, and event triggers are particularly
relevant within the insurance context, as they determine
whether insurers bear liability and which policies will
be triggered.
It can be helpful to consider scenarios as stories which
have a beginning, middle, and end, and the narrative
guides the reader through the events and their
implications. The narrative is imperative for providing
logic and reasoning to the proposed events and assists
in making the scenario more applicable and relatable.
An eective narrative can also create broader interest
and relevancy, increasing the scenario’s utility. Research
conducted in the previous steps should be applied to help
guide the narrative based on historical precedence. In
providing rich descriptive details and elaborating on the
cause-and-eect processes, a more holistic impression of
the hypothetical event can be drawn, which assists when
determining its direct and indirect impacts. One way to
expand the narrative in an insurance specic context is
by using coverage trigger pathways.
High Importance
High Uncertainty
Low Importance
High Uncertainty
High Importance
Low Uncertainty
Low Importance
Low Uncertainty
Figure 6: Impact-uncertainty risk matrix
Increasing Uncertainty
Increasing Impact
70. A return period should not be interpreted as a prediction of when the event will occur.
Instead, a return period is the probability of occurrence.
26
Scenario Best Practices: Developing Scenarios for the Insurance Industry
Coverage trigger pathways
Coverage trigger pathways are contextual details that
can be added to a scenario and are intended to stress
a specic type of insurance by impacting the insured
assets. An asset can be either tangible or intangible,
and can include: properties (location), contents, people,
products, mobile assets, organisations, projects, events,
trade agreements, contracts, or intellectual property.
71
The approach requires the users to view all the classes of
business insured in the footprint and identify potential
events which would stress that line. This can be done
in tandem with the traditional scenario narrative and
provides a series of statements to base impacts upon
when completing the scenario impact assessment.
Figure 7 illustrates an example of a scenario narrative,
and some coverage trigger pathways which could emerge
as specic insurance losses.
Designing a Scenario Narrative
The scenario narrative provides the context for a scenario and is needed when determining the direct and
indirect impacts of an event. When creating a scenario narrative, several variables should be considered.
Event Trigger: The narrative should specify the
trigger of a hazard event, for example the occurrence
of an earthquake, an act of terror, release of a new
malware, or industrial accident. Further, it should
specify any amplifying factors which might exacerbate
the event, or whether cascading events may be
triggered by an initial shock.
Location: Consider where the event trigger occurs
(if applicable) and how far reaching the impact is
felt. Furthermore, for certain types of insurance,
such as liability, the jurisdiction can dictate what
types of coverages are available, and the legal liability
organisations might hold. Indirect impacts should
also be considered in addition to primary impacts.
For example, if a terrorism event occurs in South
Korea, what international life insurance policies
might be triggered for tourists? What international
manufacturing operations would be impacted by the
interruption? With increasing global networks, event
impacts are not limited to the surrounding geographic
footprint and can quickly expand to a global scale.
Timing: The timing of an event occurrence, or a
timeline of events, should be outlined within the
scenario narrative. Variables such as the length of an
occurrence or the speed and eectiveness of a response
is critical for assessing the criticality of decisions.
Impact: The narrative should highlight who and
what is impacted by the occurrence, both directly
and indirectly, and how the severity of impacts is
distributed. Impacts, such as the eects on human
lives and livelihoods, business disruption, physical
damage and destruction, are unlikely to occur
uniformly across space and time. The narrative
should also consider individuals who face delayed
impacts, especially for occurrences which have a
longer timeline.
Recovery: Just as important as understanding the
cause and eect of the occurrence, the narrative
should also consider the recovery process. Specically,
the narrative should identify who is involved, the types
of resources recovered, and how long the recovery
takes. This directly inuences the impacts that the
occurrence has, and the scale of the event.
A downstream energy insurance claim is
triggered for pipeline physical damage
and business interruption.
Pipelines are damaged as a result of
mudslides, triggered from the hurricane.
A professional liability insurance claim is
triggered by the contractor.
A hurricane occurs in the Gulf of Mexico,
impacting the energy sector.
Scenario Narrative Coverage Trigger Pathways Impacted Insurance Line
An error by a contractor during a platform
inspection leads to structural failure during the
hurricane. Injuries are caused by the failure.
An upstream energy insurance claim is
triggered for platform physical damage
and business interruption.
Oshore marine platforms and accessories
aredamaged during the hurricane.
Figure 7: Hurricane coverage trigger pathway for the energy sector
71. (Cambridge Centre for Risk Studies, in collaboration with Risk Management Solutions, Inc. 2018)
27
Cambridge Centre for Risk Studies
Scenario variants
Once the scenario narrative is completed, its variants
can be considered. Variants are dierent versions of
the scenario where variables are adjusted to account for
uncertainty. Examples of adjustments can include the
magnitude, duration, or social reaction to the event. By
adjusting a variable, losses will increase or decrease.
Scenario variants are frequently used to show a
potential range of outcomes and their severity. The
number of scenario variants is dependent on time and
resources, but typically ranges from three to seven.
When considering the number of scenarios, the centre
stage eect
72
dictates that users are more prone to select
the middle scenario.
73
As a result, there is benet in
presenting an even number of scenarios, to dissuade the
tendency to select the centre as default.
Step 6: Assess Impacts and Materiality
Once the scenario event has been developed,
the next step is understanding what the
potential impacts are to an organisation within the
insurance industry, and/or systemic impacts to
the industry and wider social, environmental, or
economic systems. Consideration of dependencies and
interconnectivities between shocked systems with a
‘multi-threat’ approach is critical to understand the
hidden and cascading impacts beyond the expected (see
Section 3.1 on ‘systems thinking’). For example, the 2011
Tohoku earthquake triggered a tsunami that caused the
meltdown of the Fukushima Daiichi nuclear reactor
74
,
and the 2017 WannaCry cyber attack impacted the UK’s
National Health Service when sta were locked out of
their outdated operating system
75
.
Within the insurance community, specic attention is
given to the impacts on assets.
76
Assets are insured by an
insurance organisation, and should specic conditions
or circumstances arise resulting in nancial loss, a
payment would be made to the insured. Insurers will
have a catalogue of assets which they insure, and their
primary interest is how the stress test will aect these
assets. Depending on the type of asset, dierent types
of insurance
77
and insurance coverages
78
will be made
available. These categories of insurance are referred
to a ‘classes’ and are often underwritten together.
79
Accordingly, many stress tests are written to ‘stress’ a
specic insurance class, or series of classes.
When determining the assets which will be impacted by
the stress test, the following steps are recommended:
1
Determine where the impacts will occur
In the case of a physical event, this is the geographic
footprint of the direct and indirect impacts. For non-
physical events, this is identifying what systems or
networks might be impacted.
2
Identify what assets
will be impacted by the event
Consider what is insured within the footprint of
the scenario. Tangible assets would be physically
present within the footprint, while intangible assets
may be dependent on someone or something within
the scenario. Consider business operations, liability
agreements, contracts, and insured persons, in
addition to traditional physical assets.
3
Identify the incident rate
This might be the proportion of assets impacted, or the
replication of the risk. It can be helpful to consider the
incident rate as a severity scale, as it is rare that assets
all face the same degree of impact. Instead, gradation
can be applied to mimic impact variation.
4
Identify existing insurance
coverages available to asset
For the assets which are impacted by the stress test,
identify what form of insurance they would be covered
by. One asset may have multiple policies covering it for
dierent types of risks.
Upon identifying the aected assets and insurance
policies, the next step involves estimating the nancial
loss. Due to the various limits and deductibles which
are considered when paying an insurance claim, the
estimated total loss can be expressed in several dierent
forms. Common examples include macroeconomic loss,
80
ground-up loss,
81
gross loss,
82
and investment portfolio
losses.
83
These are summarised in Figure 8.
The methodology followed in calculating these loss types
varies depending on organisation and the amount of
detail available regarding regional assets. In some cases,
the specic assets and/or their exposure value may not
be known to the scenario developer. In these cases,
it is best to estimate based on insurance penetration,
historical losses, and known commercial values. If the
total insured value of an asset is available, one might
72. The centre stage eect refers the tendency for people to select the middle item when presented with a list of options (Valenzuela and Raghubir 2009a) 73 (Valenzuela and
Raghubir 2009a) 74. (Zastrow 2019) 75. (Rue et al. 2018) 76. Assets are anything tangible or intangible which is owned or can contribute value 77. Types of insurance are
products specic to a class of insurance. For example, within a marine insurance class, wet insurance includes cargo insurance, hull insurance, and marine liability insurance
78. Examples of insurance coverages include physical damage, bodily injury, or business interruption. 79. Examples of insurance classes include life, health, auto, property, or
marine. 80. Macroeconomic loss refers to losses felt by the whole economy, and considers how regional, national and global economies may react to the event 81. Ground-up
loss is the entire insurance loss, and does not include deductibles, limits or reinsurance. 82. Gross loss is the ceding company’s loss irrespective of any reinsurance recoveries
due. This can be interpreted as the ground up loss which has factored deductibles, limits and other connes, but doesn’t include reinsurance 83. Investment portfolio losses
refer to the cumulative losses seen in a collection of assets owned by an organisation or individual.
28
Scenario Best Practices: Developing Scenarios for the Insurance Industry
refer to the severity of the damage, and propose what
proportion of the asset’s total value would be aected.
Expert judgement can be a valuable resource when
estimating loss. Underwriters can be especially attuned
to relative asset values, and it is helpful to have their
guidance and review in this process. Depending on
the type of loss being calculated, deductibles, limits,
or reinsurance restrictions may also be applied to
the estimate.
Step 7: Communicate and Act
Eective communication of realised scenarios
controls the ecacy of the process. Although
it may appear trivial, a catchy name that provokes
interest is an often-overlooked scenario element that
can aid its successful uptake and communication. Then,
meaningful, comprehendible, and interesting outputs are
essential, and are likely to include both qualitative and
quantitative components addressing the scenario impacts
and materiality. It is important for the narrative to
explain and contextualise the results, and it may often be
helpful where multiple scenarios are explored to focus on
the most probable and use this as a reference to explore
others. The scenario outcomes can inform and prompt
decisions and actions where this is the intended purpose,
for example concerning an organisation’s strategic risk
management practices or to manage accumulation risk.
Consider how and to whom the scenario is delivered;
this may include internal and or external stakeholders.
Internal partners may include dierent underwriting
bodies, risk managers, or strategic planning parties,
while external partners might include regulating
authorities, governing bodies, or investing partners.
When communicating the scenario, one should consider
the audience’s background on the risk topic and the
scenario development process and ensure that they have
enough background information to interpret the ndings.
Importantly, it must be made clear what the scenario is
intending to accomplish, and how the ndings should
be interpreted. The scenario is not a prediction of future
events, but instead a thought exercise into plausible
futures. Further, stakeholders should feed back to ensure
a scenario and its results are plausible and relevant to
their needs. It is common for changes and experiments
to occur at this stage, especially if dierent variations or
severities of the scenario are being trialled. Most notably,
some may be interested in identifying what variables
will ‘tip’ the balance to the point that insurers would be
unable to nancially recover from the event.
Step 8: Evaluate and Update
To complete the scenario process, it
is encouraged to evaluate whether the
objectives of the exercise were achieved. This is
likely to involve a consultation with participants and
associated stakeholders, to review whether a scenario
is plausible and if it can be useful in developing the
users’ understanding of a risk and informing decisions.
Listen to contrary opinions, as a method to overcome
groupthink and build on insights from a range of
sources. Consider if the stress test scenario answers the
initial problem, and if the severity of the event meets
the intended targets. This process has been expressed
in a linear step-by-step process, but it is critical to use
this evaluation process to identify and address any
weaknesses in the scenario and applied analytics in an
iterative process.
Sometimes, the most interesting and insightful
scenarios are those that initially appear to be the least
probable. Scenarios have varying lifespans, intended
to be discarded after the exercise is nished or to be
kept and reused over a period of years.
84
Therefore, it is
important to acknowledge that scenarios are dynamic.
The possibility and character of a scenario will change
over time as controlling factors evolve, as will its impact
on the insurance industry – including practices, product
oerings, and exposures – and wider society – including
social, economic, and environmental characteristics –
and so it should be updated periodically to maintain
relevance and continued utility.
84. (Roxburgh 2009)
Co-share Limit
Deductible or Self
Insured Retention (SIR)
Total Insured Value
Gross Loss
Ground Up Loss
Figure 8: Dimensions of insurance loss
29
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4.3 Considerations and Constraints
When discussing scenarios, there is potential to overemphasise their mechanics and impact without
providing a balanced critique. This section of the report is dedicated to highlighting the limitations of
scenarios and raising awareness of appropriate precautions that should be considered.
Constraints of Probability
Probability is the likelihood of an event occurring and
has guided extensive decision making in the insurance
industry. The application of probabilities to scenarios
has also been a point of contention, however, as there
are concerns that it may introduce false condence and
awareness to areas of high uncertainty. To appreciate
these concerns, it is helpful to explore probability
as a concept. Probability is usually understood via a
frequency calculation: the number of ways of achieving
a specic outcome, divided by the total number of
possible outcomes. Underpinning probability theory, the
Kolmogorov axioms state that you must know the event
space, or all potential outcomes, in order to dene the
likelihood of one specic outcome. This perspective implies
that probability requires the subject exist within a closed
system, where all potential future events can be identied
at present and can be accounted for when considering
likelihood.
85
As this is not an option in practice, insurers
often accept the ergodic axiom, which suggests that the
future is going to reect the past and present and use that
to guide their prediction of the future.
86
This introduces
a series of problems when considering emerging risks,
or events with limited historical precedent, and fails
to prepare users for events which have never been
experienced before. In these environments, probabilities
which are dependent on historical events may be
misleading, or may imply an over-condence that all
potential outcomes have been explored and addressed.
87
Common critiques of the use of probability when
considering future risks are not aimed at eliminating
the use of probabilities, but instead at addressing the
uncertainty and assumptions that they bring.
A related and more theoretical concern is that these
probabilistic scenarios remain deterministic in their
assumptions. This is because the probabilities of future
events are only identifying specic outcomes, which
are determined by the modeller.
88
For example, when
considering the possibility of a selected risk occurring
in a specic location, one may reduce all outcomes to a
short list of, say, four outcomes of dierent severities
and likelihoods. While this may be helpful in simplifying
the analysis of that risk, it may also lead to an incorrect
sense of certainty that the future may only materialise
as one of these four outcomes, and introduces a new
risk of not accurately representing the uncertainty of the
future.
89
Furthermore, one must recognise that probability
applications do have a place but cannot always be applied.
For some risks, the probability is essentially irrelevant, as
the outcome is too crucial. Examples include extreme tail
risks, or highly unique events which cannot be aggregated
into a composite group.
90
In such situations, probabilities
are less important than recognising who is responsible
as the risk holder of last resort, and understanding their
preparation and response to that risk given its potential
impact and available resources.
Cognitive Bias
When designing and using a scenario, one must
consider the eects of cognitive bias on decision making.
Cognitive bias is an umbrella term which describes
the input of subjectivity onto decision making and our
interactions with the environment. These biases can
guide what risks we choose to focus upon, and how we
interpret given information.
When discussing cognitive bias, it is helpful to provide
some perspective as to why it is important, and why it
occurs. The world provides the brain with a complex
environment with enormous amounts of information
to process. This complexity is compounded when
decisions need to be made. To reduce the eort and
delay until a decision is made, cognitive biases develop
based on interactions with the environment. These
cognitive simplications are commonly referred to
‘heuristics’ and can be thought of as mental shortcuts or
our ‘intuition’.
While an individual’s cognitive biases and developed
heuristics likely developed for adaptive reasons to
simplify decision making, these intuitive judgements
based on intuitive probability and frequency judgements
have the potential to lead to judgement errors. Although
many of these errors are unavoidable, we can be mindful
of their impact and take precautionary steps if needed.
As a rst example of a bias, we pick out overcondence
which describes the tendency to be overly optimistic
in ignorance of contrary evidence, often in the context
of setting a goal. Nobel laureate Daniel Kahneman
identies overcondence as “the most signicant of the
cognitive biases”.
91
85. (Derbyshire 2017a) 86. (Derbyshire 2017a; Davidson 1991) 87. (Roxburgh 2009)
88. (Derbyshire 2017a) 89. (Derbyshire 2017a) 90. (Derbyshire 2017b) 91. (Kahneman 2011)
30
Scenario Best Practices: Developing Scenarios for the Insurance Industry
Below we discuss two common biases inuencing scenario development.
Availability Bias
Decisions on probability and judgements are based on the
ease with which relevant instances come to mind
92
.
Frequent occurrences of an event mean individuals have
plenty of relevant experience to draw from when judging
the probability of an event, so basing judgments on
availability is sensible and people’s frequency judgments
are often very accurate. However, availability can be
biased if our experience of past events does not reect the
true frequency or if an event is easier to recall for a reason
other than its frequency.
These biases can be introduced by the environment or the
individual. Rare events are often given disproportionate
publicity and are correspondingly more mentally
available than their true frequency would merit.
Similarly, events that individuals have experienced
personally with an emotional response are much more
readily available.
The availability bias is helpful to consider when
evaluating risks, as we generally underrepresent common
risks which do not receive as much attention while we
over represent recent heavily reported risks, or risks
which we have experienced ourselves. When applying
the availability bias to scenario development, one should
attempt to understand the viewpoint users of the scenario
have, to create scenarios that make the risk accessible
and personal.
Anchoring Bias
Final estimates or judgements are often reached by
adjusting away from an initial “anchor” value, but these
adjustments are often insucient.
93
Anchoring bias occurs when we focus decision making on
an initial piece of information. An initial value is used as
a reference when evaluating and comparing additional
information. The outcome may be skewed or inuenced
by the initial, possibly arbitrary, anchor. An example of
this may be seen when estimating catastrophic losses.
We often base our estimated losses on a historical
precedent and are unprepared when a substantial
variation occurs, such as was seen in Hurricane Andrew
or the World Trade Centre terrorism attack. Stress
test scenarios are routinely used to introduce higher
anchoring values, which insurers can plan against.
Accordingly, stress test scenarios should be gauged to
stress the system and introduce new precedents for
insurers to plan against.
Communication Failures and Misinterpretations of Outcomes
Scenario modelling outcomes are most eective when
there is a governance structure in place that promotes
clear lines of communication to external and internal
stakeholders. Eective communication enhances risk
management by providing information that may be used
to enhance processes, identify emerging issues, and aid
in overall decision making.
94
If scenario analysis is not
communicated suciently, the outputs of the scenario
could be ignored or the misinterpreted which then
negatively impacts business performance.
95
One of the most common misinterpretations which was
reported via this report’s consultation process was the
interpretation of results as predictions rather than as
possible futures. Scenarios in an insurance context are
not developed to assist insurers in preparing for a specic
incident, as it is highly improbable that the specic
outcome will occur. Instead, they must be interpreted as
thought exercises. By ensuring that the communication
eorts reect this dierentiation, scenarios can be
eectively used for their intended purpose.
When to Avoid Scenarios
In certain cases, uncertainty surrounding a risk
may be so great that a scenario to explore it
cannot provide any reliable insights. Scenarios
may be harmful in generating a groupthink of
their own, whereby they inform the belief that
only a dened set of outcomes are possible.
Practitioners should be wary of thinking that they
have all reasonable scenarios when there are quite
dierent possibilities that remain unknown.
96
92. (Tversky and Kahneman 1974) 93. (Tversky and Kahneman 1974)
94. (North American CRO Council 2013) 95. (Roxburgh 2009) 96. (Roxburgh 2009)
31
Cambridge Centre for Risk Studies
32
Scenario Best Practices: Developing Scenarios for the Insurance Industry
5. Scenario Development
Case Study: Business Blackout
This section presents an example of a s
cenario’s development process, using
the method proposed in Section 4 of this report. The example scenario is
based upon the 2015 Lloyd’s Business Blackout scenario
97
, developed to
address emerging cyber risk within the insurance industry. The case study
illustrates a practical example of each of the eight s
cenario development steps.
Step 1: Scope the Risk
The purpose of the Business Blackout
scenario was to develop a scenario that would
explore the potential for losses to occur in many dierent
lines of insurance as a result of a cyber attack against
the US power grid. Of concern was the potential for
insured parties to experience losses that are indirectly
covered within insurance policy terms and conditions,
or are ambiguous, not explicitly excluded in policy
wordings, known as ‘silent’ cyber coverage. The scenario
sought to identify how much silent cyber coverage might
be triggered under certain conditions and to explore
whether there might be a need to take more proactive
actions to identify and clarify this coverage. In this
case, the risk – a cyber attack – was clearly dened and
explicitly motivated the exercise, with the objective to
explore the uncertainty around the impact of a severe
event. A specialist working group of researchers and
insurance specialists drew up a long list of potential
candidate scenarios and prioritised a scenario where
there was a cyber attack that would cause a widespread
power outage in the electrical grid in the United States.
To assist with the scenario planning, the development
team developed a problem statement. What are the
potential insurance impacts of an extreme power loss
caused by a cyber attack on the US electrical power grid?
Step 2: Conduct Background Research
Several dierent topics were researched
to better understand the risk landscape.
Dominant questions for discussion included:
What insurance policies might pay out in the event
of a lengthy power outage, and how would it be
dierent if the proximate cause were to be a malicious
cyber attack?
How much of a threat does cyber pose to critical
national infrastructure, and what evidence is there for
cyber hackers targeting the energy sector?
Is it possible for a cyber attack to cause a power
outage, and how severe could it potentially be?
What sort of vulnerabilities could be exploited,
and what are the implications for the geographical
extent and duration of outages that would occur?
How often and extensive have outages been to the US
electrical grid from non-cyber causes?
How did it occur and what was the impact?
Have there been “near misses”
98
from cyber attacks
which have occurred before?
Where are the system vulnerabilities within an
electrical grid?
How does the electricity grid work, what is its
structure and generating capacity?
What cyber security measures are in place to
protect the generators, transmission systems, and
distribution networks for electricity grids?
What are future developments for the electricity
grid (i.e. Smart Grids)
What are the planned responses to an electrical
grid outage?
Are components of the response susceptible
to errors?
97. (Cambridge Centre for Risk Studies 2015)
98. Near misses refers to an event which had the potential for harm but did not materialise.
33
Cambridge Centre for Risk Studies
What type of cyber insurance (both silent and
armative) would be impacted by a cyber
physical scenario?
How big would this be?
When approaching these questions, the team consulted
various experts who were familiar with the topic.
These experts were found through research networks,
recommendations, and introductions, and included
members from the insurance industry, the government,
the energy industry, and the cyber security community.
Each expert brought unique insight to the scenario, and
were aware of dierent vulnerabilities, histories, and
responses. In addition to the subject matter experts, a
wide number of resources were also utilised, including
government records, media, and reference databases.
Research and background consultation was not restricted
to this period of the exercise, but continued throughout
the scenario’s development.
Step 3: Frame the Scenario
In the initial stages of development, the
development team participated in a thought
exercise to decide what scenario methodology to use. The
team discussed the framing questions and agreed in the
scenario’s direction. These framing questions entailed:
1
What is the scenario for?
The scenario is being developed to understand an
emerging risk, cyber, which remains a novel and
uncertain threat for which there is only a short history
of historical precedents.
2
How can the scenario benet stakeholders?
The scenario is intending to address uncertainty and
expand the insurance industry’s understanding of
cyber risk and insurance exposures.
3
On what timescale does the risk materialise?
The scenario is intended to be a sudden-onset, shock
risk scenario.
4
What is the scenario outcome?
The scenario intends to ask ‘what if’, and is primarily
an exploratory scenario, imagining a future event for
which there is no close precedent.
5
Who owns and contributes to the
scenario process?
The scenario is intended to be an expert-driven,
top-down exercise, and delivered via a report,
hosted in the public domain, for repeated use by
insurance practitioners.
6
Is the scenario required to dene the
likelihood of an outcome?
The scenario involves a high degree of uncertainty and
is speculative in nature and is therefore deterministic.
It includes three scenario variants of varying severity
and probability, expressed as annual probabilities (for
example, 1 in 50 years).
Step 4: Develop Candidate Scenarios
During the research process, the development
team compiled potential candidate scenarios
for processes that might trigger an electrical grid failure.
These candidate scenarios were based on discussions, near
misses, historical events, and key system vulnerabilities,
and initially these were very loosely dened. Several
emerged from the list of possible scenarios as viable
options. These received further investigation to consider
their plausibility and were then reviewed by panels of
cyber security experts to assess their credibility. This led
to the development of three candidate scenarios.
1
Hackers manipulate electricity generators’ control
networks, causing the generators to malfunction. The
generators become damaged, and lead to a power outage.
2
Hackers interfere with the energy market and falsify
a series of purchases. This leads to an oversupply
combined with a decrease in demand in the market,
triggering bankruptcy and market failure.
3
Specic brands of phasor measurement units are
manipulated with known software vulnerabilities,
causing randomised damage across generators. The
response to these attacks, including investigating their
cause and replacing the generators, lasts for years.
The three scenarios were reviewed at a workshop
attended by external stakeholders and subject matter
experts and received feedback and recommendations
on each scenarios’ feasibility, severity, and interest.
Internally, the development team considered which
scenario best answered the question proposed and was
best positioned to address the uncertainty of a physical
cyber attack. Scenario 1 was considered the best suited
scenario and was further dened during the workshop.
1
A Malware infects generator control rooms and allows
hackers to disable safety systems which would usually
protect the generators from desynchronisation events.
Generators are manipulated to overheat and catch re.
34
Scenario Best Practices: Developing Scenarios for the Insurance Industry
Step 5: Develop Narrative
Upon deciding the basis for the event, the
surrounding narrative and details began
to develop. The development team conducted further
research to identify the location for such an event to
occur and cause maximum impact, and how long the
crisis might last before emergency provisions became
available. A list of potential impacts was also developed,
largely based upon smaller scale precedents. A narrative
was created for the scenario to provide the structure for
the loss modelling and to communicate the outcomes.
The following is a summary of the scenario’s narrative:
“A piece of malware (the ‘Erebos’ trojan) infects
electricity generation control rooms in parts of the
North-eastern United States. The malware goes
undetected until it is triggered on a particular day when
it releases its payload which tries to take control of
generators with specic vulnerabilities. In this scenario
it nds 50 generators that it can control, and forces
them to overload and burn out, in some cases causing
additional res and explosions. This temporarily
destabilises the North-eastern United States regional
grid and causes some sustained outages. While power
is restored to some areas within 24 hours, other parts
of the region remain without electricity for a number of
weeks. Economic impacts include direct damage to assets
and infrastructure, decline in sales revenue to electricity
supply companies, loss of sales revenue to business and
disruption to the supply chain”.
99
To compliment the narrative and assist in the modelling
process, a series of coverage trigger pathways were
also proposed. These statements aided in determining
what the asset was, and what line of business was being
triggered by the impact.
For example, when discussing damage to generators, the
coverage trigger pathway stated:
1
Commercial generators are damaged by the electrical
re, and are non-repairable due to the extent
of damage.
Step 6: Assess Impacts and Materiality
With the narrative in place, the next step was
calculating the event consequences. Within
this scenario, the development team decided to calculate
ground up loss. A portfolio loss guide was also written
for how insurers could use the scenario to estimate
the exposure of, and associated losses to, their own
portfolios. Losses were calculated individually for each
asset type.
An example of the loss calculation processes used for
perishables is described below.
1
Determine where the impacts will occur: The
power outages occur in 15 North Eastern U.S. states, in
regions dependent on compromised generators.
2
Identify what assets will be impacted by
the event: Perishables, which require refrigeration,
are routinely found in culinary, hospitality, grocery,
and medical properties. Marine cargo and chemical
facilities also routinely store perishable products.
3
Identify the incident rate: Of all potential
properties, assume a fraction do not carry any
perishables. Assume an additional fraction have an
emergency generator or alternative power source. Of
the remaining properties, we assume that they do not
all have the same length of outage, with some lasting
days, while others’ weeks. A severity gradient was
applied to account for this variation of damage.
4
Identify existing insurance coverages available
to asset: The insurance class for the perishable assets
depend on the sector from which they arise, either
marine insurance or commercial property insurance.
The coverage is assumed to be property damage in
both cases.
5
Calculate the loss based on asset value: The
loss values were calculated based upon the number
of damaged perishables, the ratio of damage, and
the value of the perishable. The sum of these values
($21.4bn) generated a rst order estimate of the loss.
During the loss calculation process, interviews were
conducted on an ongoing basis. This assisted in
developing parameters upon which to base estimates.
99. (Cambridge Centre for Risk Studies 2015)
35
Cambridge Centre for Risk Studies
Step 7: Communicate and Act
Once losses were calculated, the complete
scenario and results, were reviewed by the
initial consultation group. This aided in fact checking the
proposed events and outcomes and adding additional
recommendations that may initially have not been
included. The industry loss estimation methods were
reviewed with a number of insurers before the scenario
was nalised. Examples of questions posed during the
iterative process include:
1
Is the outage length plausible from a cyber attack?
2
Are there any missing logical steps in the narrative?
3
Are the losses in the range which you would expect?
4
Are parameters used in the modelling consistent with
your experience with losses in the area?
Through the publication of the report, the ndings were
communicated to community stakeholders. A public
launch was held to mark the release of the report and
disseminate it to a wider audience.
Step 8: Evaluate and Update
The scenario has been widely applied
within the insurance industry by a variety of
practitioners and was adapted for further use in cyber
models. The scenario remains accessible and relevant
years after development, although users of this scenario
have called for an update to maintain its validity in the
changing cyber and insurance markets.
The physical property insurance market has grown
and changed in terms of how it covers cyber risk. The
scenario will be updated as part as a periodic review
process, to ensure it remains useful.
36
Scenario Best Practices: Developing Scenarios for the Insurance Industry
6. Future Perspectives on Scenarios
Scenario development is a constantly developing eld of research. Scenario methodologies and
applications have advanced substantially in the past decades, with further changes and growth to come.
Two of the greatest changes anticipated within the insurance modelling community are the increased
availability of data, and the potential for customised modelling supported by machine learning.
Traditionally, insurance scenario modelling has been
dependent on the availability of structured internal data,
produced on a pre-determined frequency (monthly,
annually, quarterly etc.),
100
and desktop research
conducted by underwriters and sta. Alternatively,
external catastrophe modelling approaches aim to
understand potential future losses due to catastrophic,
tail risk events, with synthetic loss events in the future.
The ‘Fourth Industrial Revolution’ has spawned a new
generation of data collection tools that presents an
opportunity for the insurance industry’s use. Advanced
data mining techniques have generated a substantial
increase in the availability and frequency of large and
unstructured data sets that can be used for real-time
scenario analytics. Much of the data is third-party
mined from digital platforms such as social media and is
therefore used mainly as a rich source of data for insights
into consumer behaviour.
101
With an estimated 2.5 quintillion bytes of data being
created daily, the insurance industry is increasingly
using big data and machine learning techniques
to analyse large and unstructured data sets which
may aid the scenario development process.
102
Open-
sourced data management tools such as Apache and
Hadoop are increasingly being used by insurers to
disseminate structured and unstructured data sets in
short time horizons. This has aided in the development
of real-time analytics in the insurance industry.
103
Real-time behavioural data opens new opportunities
in understanding behavioural risks that have been
previously dicult to forecast.
Consumer specic data also heralds the possibility for
personalised scenario modelling, based on real-time
monitoring and visualisation of consumer behaviour.
Examples of customised data collection have been
increasingly seen in auto and health insurances, which
have been introducing personal monitoring devices to
provide more accurate premiums to consumers.
104
The insurance industry is lagging behind many other
sectors in investment into AI and machine learning,
with only 1.33% of insurance companies investing in AI
in 2017 compared with 32% of internet and software
companies.
105
However, a survey by Deloitte in 2017
estimated that 95% of insurance executives intend to
start or continue to invest in AI capabilities. Indeed,
investment in AI in the insurance industry increased by
68% between 2011 and 2014.
106
As investment in machine
learning and AI tools continues to grow, scenario
development will increasingly involve these tools to
create more complex and comprehensive scenarios.
100. (Clarke and Libarikian 2014) 101. (Clarke and Libarikian 2014; Allen 2018)
102. (Schroeck and Shockely 2012) 103. (Schroeck and Shockely 2012)
104. (Insurance Business UK 2018) 105. (Deloitte Digital 2017) 106. (Deloitte Digital 2017)
37
Cambridge Centre for Risk Studies
7. Glossary
Accumulation: The combined total risks triggered by a
single hazard event.
Backcasting: A scenario technique which identies
a future state and then works backwards to determine
possible paths to this future from the present state.
Baseline Scenario: An assumed future with no explicit
deviations, used to compare possible futures against.
Cascading Events: An event which triggers an event of
another type, to cause a more extreme event.
Counterfactual Scenarios: An alternative outcome of
a historical event, had a specic hypothetical intervention
occurred, or a real intervention had not.
Decision Making Under Deep Uncertainty: An
emerging paradigm comprising a variety of approaches
to cope with uncertainty with robust decisions.
Deep Uncertainty: Exists when various parties to
a decision do not know, or cannot agree on, how a
complex system works, the probability of possible future
states, and how important the various consequences of
interest are.
107
Deterministic Approach: An examination
of the impacts of a single event, dened by the
scenario developer.
Due Diligence: Care which is taken to avoid harm or
damage to other persons or property.
Emerging Risk: An emerging risk is a new risk,
changing risk, or novel combination of risks for which
the broad impacts, costs and optimal management
strategies are not yet well understood.
Forecast: The most probable prediction that something
will happen in the future.
Hazard: A natural or anthropogenic process or
phenomenon that may result in negative social,
economic, or environmental consequences. A hazard
event is the manifestation of a hazard in a particular time
and place.
108
Insurance: A contract where an entity agrees to pay an
agreed amount in the case of a specic event occurring.
Insurance is a form of risk transfer.
Narrative: A descriptive summary of the events
occurring within a scenario. Also known as a storyline.
Prediction: A subjective (probabilistic) statement that
something will happen in the future.
109
Probabilistic Approach: An examination
of all potential outcomes, and their estimated
likelihood (probability).
Projection: A probabilistic statement that something
will happen under certain conditions, allowing for
signicant changes in the boundary conditions that
might inuence a prediction.
110
Resource Allowance: The amount of resources that
can be spent on a specic task. Examples of resources
can include time, money or persons.
Risk: A hazard event with the potential to cause
economic and/or societal losses, determined
probabilistically as a function of hazard, exposure
and vulnerability.
Scenario: Plausible descriptions of how the future
might develop, based on a coherent and internally
consistent set of assumptions about key deterministic
relationships and driving forces.
111
Shock Risk: Extreme, sudden-onset hazard events that
emerge quickly or unexpectedly.
Stress Test: A scenario designed to assess the
idiosyncratic vulnerabilities of an organisation to a
hazard event.
Tail Risk: Rare events that occur more than three
standard deviations from the expected, most probable
outcome. The term can be used more generally to
describe highly unlikely extreme outcomes.
Trend Risk: Slow-onset hazard phenomena that
emerge gradually over time.
Uncertainty: A potential outcome with an unknown
probability, which is therefore uncontrollable.
Vulnerability: “The conditions determined by physical,
social, economic and environmental factors or processes
which increase the susceptibility of an individual,
a community, assets or systems to the impacts of
hazards”.
112
107. (Kwakkel 2017) 108. (UNISDR 2017) 109. (MacCracken 2001)
110. (MacCracken 2001) 111. (Van Vuuren et al. 2012) 112. (UNISDR 2017)
38
Scenario Best Practices: Developing Scenarios for the Insurance Industry
39
Cambridge Centre for Risk Studies
8. References
Alford, Carlos L. 2017. ‘The Department of Defense
Eort to Counterting the Cyberterrorism Threat:
Is the Threat Real or Hyperbole?’ National Defense
University: Joint Forces Sta College. https://www.hsdl.
org/?abstract&did=805424.
Allen, Marshall. 2018. ‘Health Insurers Are Vacuuming Up
Details About You — And It Could Raise Your Rates’.
ProPublica. 17 July 2018. https://www.propublica.org/
article/health-insurers-are-vacuuming-up-details-about-
you-and-it-could-raise-your-rates.
Amer, Muhammad, Tugrul U. Daim, and Antonie Jetter. 2013.
‘A Review of Scenario Planning’. Futures 46 (February):
23–40. https://doi.org/10.1016/j.futures.2012.10.003.
Beven, Keith J., and Ruth E. Alcock. 2012. ‘Modelling
Everything Everywhere: A New Approach to Decision-
Making for Water Management under Uncertainty’.
Freshwater Biology 57 (s1): 124–32. https://doi.
org/10.1111/j.1365-2427.2011.02592.x.
Birkmann, Joern, Susan L. Cutter, Dale S. Rothman,
Torsten Welle, Matthias Garschagen, Bas van Ruijven,
Brian O’Neill, et al. 2015. ‘Scenarios for Vulnerability:
Opportunities and Constraints in the Context of Climate
Change and Disaster Risk’. Climatic Change 133 (1): 53–68.
https://doi.org/10.1007/s10584-013-0913-2.
Boonen, Tim J. 2017. ‘Solvency II Solvency Capital
Requirement for Life Insurance Companies Based on
Expected Shortfall’. European Actuarial Journal 7 (2):
405–34. https://doi.org/10.1007/s13385-017-0160-4.
Broadhurst, Roderic, Hannah Woodford-Smith, Donald
Maxim, Bianca Sabol, Stephanie Orlando, Ben Chapman-
Schmidt, and Mamoun Alazab. 2017. ‘Cyber Terrorism:
Research Review: Research Report of the Australian
National University Cybercrime Observatory for the
Korean Institute of Criminology’. SSRN Scholarly Paper ID
2984101. Rochester, NY: Social Science Research Network.
https://papers.ssrn.com/abstract=2984101.
Cambridge Centre for Risk Studies. 2015. ‘Lloyd’s Business
Blackout Scenario’. Emerging Risk Report. Cambridge
Centre for Risk Studies at the University of Cambridge
Judge Business School. https://www.jbs.cam.ac.uk/
faculty-research/centres/risk/publications/technology-
and-space/lloyds-business-blackout-scenario/.
Cambridge Centre for Risk Studies, in collaboration with
Lighthill Risk Network, 2019. Scenario Best Practices:
Developing Scenarios for Disaster Risk Reduction.
Cambridge Centre for Risk Studies at the University of
Cambridge Judge Business School.
Cambridge Centre for Risk Studies, in collaboration with Risk
Management Solutions, Inc. 2018. ‘Multi-Line Insurance
Exposure Management Data Denitions Document v1.0’.
Cambridge Centre for Risk Studies at the University of
Cambridge Judge Business School. https://www.jbs.cam.
ac.uk/leadmin/user_upload/research/centres/risk/
downloads/crs-geac-data-denitions-document.pdf.
Clarke, Richard, and Ari Libarikian. 2014. ‘Unleashing the
Value of Advanced Analytics in Insurance’. McKinsey
& Company. https://www.mckinsey.com/industries/
nancial-services/our-insights/unleashing-the-value-of-
advanced-analytics-in-insurance.
Cummins, J. David. 2000. ‘Allocation of Capital
in the Insurance Industry’. Risk Management
and Insurance Review 3 (1): 7–27. https://doi.
org/10.1111/j.1540-6296.2000.tb00013.x.
Davidson, Paul. 1991. ‘Is Probability Theory Relevant for
Uncertainty? A Post Keynesian Perspective’. Journal
of Economic Perspectives 5 (1): 129–43. https://doi.
org/10.1257/jep.5.1.129.
Deloitte Digital. 2017. ‘From Mystery to Mastery: Unlocking
the Business Value of Artical Intelligence in the Insurance
Industry’. Deloitte Digital. https://www2.deloitte.com/
content/dam/Deloitte/xe/Documents/nancial-services/
Articial-Intelligence-in-Insurance.pdf.
Derbyshire, James. 2017a. ‘The Siren Call of Probability:
Dangers Associated with Using Probability for
Consideration of the Future’. Futures 88 (April): 43–54.
https://doi.org/10.1016/j.futures.2017.03.011.
———. 2017b. ‘Potential Surprise Theory as a Theoretical
Foundation for Scenario Planning’. Technological
Forecasting and Social Change 124 (November): 77–87.
https://doi.org/10.1016/j.techfore.2016.05.008.
Dreborg, Karl H. 1996. ‘Essence of Backcasting’.
Futures 28 (9): 813–28. https://doi.org/10.1016/S0016-
3287(96)00044-4.
Durance, Philippe, and Michel Godet. 2010. ‘Scenario Building:
Uses and Abuses’. Technological Forecasting and Social
Change, Strategic Foresight, 77 (9): 1488–92. https://doi.
org/10.1016/j.techfore.2010.06.007.
Evan, Tamara, Eireann Leverett, Simon Rue, Andrew
Coburn, James Bourdeau, Rohan Gunaratna, and Daniel
Ralph. 2017. ‘Cyber Terrorism: Assessment of the Threat to
Insurance’. Cambridge Risk Framework Series. University
of Cambridge: Cambridge Centre for Risk Studies. https://
www.jbs.cam.ac.uk/leadmin/user_upload/research/
centres/risk/downloads/pool-re-cyber-terrorism.pdf.
Financial Services Commission. 2009. ‘Basel II: Pillar 2 - The
ICAAP & The SREP’. Guidance Note. Gibraltar: Financial
Services Commission. http://www.fsc.gi/uploads/legacy/
download/adobe/banking/noteiccaapsrep.pdf.
GIRO Working Party. 2016. ‘Integrating Pricing & Capital
Modelling’. https://www.actuaries.org.uk/system/les/
documents/pdf/Crozet.pdf.
Grant, Matthew. 2015. ‘What Can the Insurance Market Teach
Banks About Stress Tests? | The RMS Blog’.
The RMS Blog (blog). 2015. https://www.rms.com/
blog/2015/08/03/what-can-the-insurance-market-teach-
banks-about-stress-tests/.
40
Scenario Best Practices: Developing Scenarios for the Insurance Industry
Haasnoot, Marjolijn, Jan H. Kwakkel, Warren E. Walker, and
Judith ter Maat. 2013. ‘Dynamic Adaptive Policy Pathways:
A Method for Crafting Robust Decisions for a Deeply
Uncertain World’. Global Environmental Change 23 (2):
485–98. https://doi.org/10.1016/j.gloenvcha.2012.12.006.
Hallegatte, Stéphane, Ankur Shah, Robert Lempert, Casey
Brown, and Stuart Gill. 2012. ‘Investment Decision
Making under Deep Uncertainty’. World Bank Group,
Policy Research Working Papers, 6193. https://doi.
org/10.1596/1813-9450-6193.
Henrichs, Thomas, Monika Zurek, Bas Eickhout, Kasper
Kok, Ciara Raudsepp-Hearne, Teresa Ribeiro, Detlef van
Vuuren, and Axel Volkery. 2010. ‘Scenario Development
and Analysis for Forward-Looking Ecosystem
Assessments’. Ecosystems and Human Well-Being: A
Manual for Assessment Practitioners, 151–219.
House of Commons Treasury Committee. 2018. ‘The Solvency
II Directive and Its Impact on the UK Insurance Industry:
Bank of England Response to the Committee’s Third
Report of Session 2017-2019’. Second Special Report of
Session 2017-19. House of Commons.
https://publications.parliament.uk/pa/cm201719/
cmselect/cmtreasy/863/863.pdf.
Insurance Business UK. 2018. ‘How Telematics Is Transforming
the Car Insurance Landscape’. Insurance Business UK.
17 December 2018. https://www.insurancebusinessmag.
com/uk/opinion/how-telematics-is-transforming-the-car-
insurance-landscape-119099.aspx.
Insurance Journal. 2018. ‘Pool Re Extends Retrocession
Program to $2.9B with Cyber Terrorism Now
Covered’. Insurance Journal. 1 March 2018.
https://www.insurancejournal.com/news/
international/2018/03/01/482001.htm.
Jeerson, Michael. 2012. ‘Shell Scenarios: What Really
Happened in the 1970s and What May Be Learned for
Current World Prospects’. Technological Forecasting and
Social Change 79 (1): 186–97. https://doi.org/10.1016/j.
techfore.2011.08.007.
Kahn, Herman. 1961. ‘On Thermonuclear War’. Princeton:
Princeton University Press.
Kahneman, Daniel. 2011. Thinking, Fast and Slow. Macmillan.
Kauman, Draper L. 1980. Systems One: An Introduction to
Systems Thinking. Pegasus Communications.
Kim, Seong Dae. 2012. ‘Characterizing Unknown Unknowns’.
In . North America, Vancouver, British Columbia, Canada.
Newtown Square, PA: Project Management Institute.
https://www.pmi.org/learning/library/characterizing-
unknown-unknowns-6077.
Krvavych, Yuriy. 2018. ‘Making Use of Internal Capital Models’.
presented at the ASTIN Colloquium, The Hague, May 21.
https://web.actuaries.ie/sites/default/les/erm-resources/
making_use_of_internal_capital_models.pdf.
Kwakkel, Jan H. 2017. ‘Managing Deep Uncertainty:
Exploratory Modeling, Adaptive Plans and Joint Sense
Making’. Integration and Implementation Insights (blog).
14 August 2017. https://i2insights.org/2017/08/15/
managing-deep-uncertainty/.
Kwakkel, Jan H., Warren E. Walker, and Marjolijn Haasnoot.
2016. ‘Coping with the Wickedness of Public Policy
Problems: Approaches for Decision Making under Deep
Uncertainty’. Journal of Water Resources Planning and
Management 142 (3): 01816001. https://doi.org/10.1061/
(ASCE)WR.1943-5452.0000626.
Lempert, Robert J., and Nidhi Kalra. 2011. ‘Managing Climate
Risks in Developing Countries with Robust Decision
Making’. In .
Lempert, Robert J., Steven W. Popper, and Steven C. Bankes.
2003. Shaping the Next One Hundred Years: New Methods
for Quantitative, Long-Term Policy Analysis. https://www.
rand.org/pubs/monograph_reports/MR1626.html.
Lempert, Robert J., Steven W. Popper, David G. Groves, Nidhi
Kalra, Jordan R. Fischbach, Steven C. Bankes, Benjamin
P. Bryant, et al. 2013. ‘Making Good Decisions Without
Predictions: Robust Decision Making for Planning Under
Deep Uncertainty’. Product Page. 2013. https://www.rand.
org/pubs/research_briefs/RB9701.html.
Lloyd’s of London. n.d. ‘What Is Solvency II?’ Lloyd’s of
London. Accessed 12 December 2018. https://www.lloyds.
com/market-resources/regulatory/solvency-ii/about/
what-is-solvency-ii.
Lorenz, Edward N. 1963. ‘Deterministic Nonperiodic Flow’.
Journal of the Atmospheric Sciences 20 (2): 130–41.
https://doi.org/10.1175/1520-0469(1963)020<0130:DNF
>2.0.CO;2.
MacCracken, Mike. 2001. ‘Prediction versus Projection -
Forecast versus Possibility’. WeatherZine, 26 February
2001, 26 edition. https://sciencepolicy.colorado.edu/zine/
archives/1-29/26/guest.html.
Mietzner, Dana, and Guido Reger. 2005. ‘Advantages and
Disadvantages of Scenario Approaches for Strategic
Foresight’. International Journal of Technology
Intelligence and Planning 1 (2): 220. https://doi.
org/10.1504/IJTIP.2005.006516.
North American CRO Council. 2013. ‘Scenario Analysis
Principles and Practices in the Insurance Industry’. North
American CRO Council. http://crocouncil.org/images/
CRO_Council_-_Stress_and_Scenario_Testing_Paper_
FINAL.pdf.
Olabisi, Laura Schmitt. 2017. ‘Dealing with Deep Uncertainty:
Scenarios’. Integration and Implementation Insights
(blog). 5 January 2017. https://i2insights.org/2017/01/05/
deep-uncertainty-and-scenarios/.
Popper, Steven W., James Grin, Claude Berrebi, Thomas
Light, and Endy M. Daehner. 2009. ‘Natural Gas and
Israel’s Energy Future’. Product Page. 2009. https://www.
rand.org/pubs/technical_reports/TR747.html.
Renard, Philippe, Andres Alcolea, and David Ginsbourger.
2013. ‘Stochastic versus Deterministic Approaches’. In
Environmental Modelling, 133–49. John Wiley & Sons,
Ltd. https://doi.org/10.1002/9781118351475.ch8.
Riddell, Graeme A., Hedwig van Delden, Graeme C. Dandy,
Aaron C. Zecchin, and Holger R. Maier. 2018. ‘Enhancing
the Policy Relevance of Exploratory Scenarios: Generic
Approach and Application to Disaster Risk Reduction’.
Futures 99 (May): 1–15. https://doi.org/10.1016/j.
futures.2018.03.006.
41
Cambridge Centre for Risk Studies
Risk Management Solutions Inc, in collaboration with
Cambridge Centre for Risk Studies. 2016. ‘Managing
Cyber Insurance Accumulation Risk’. Risk Management
Solutions Inc, in collaboration with Cambridge Centre
for Risk Studies at the University of Cambridge Judge
Business School. https://www.jbs.cam.ac.uk/leadmin/
user_upload/research/centres/risk/downloads/crs-rms-
managing-cyber-insurance-accumulation-risk.pdf.
Robinson, John B. 1990. ‘Futures under Glass: A Recipe for
People Who Hate to Predict’. Futures 22 (8): 820–42.
https://doi.org/10.1016/0016-3287(90)90018-D.
Roxburgh, Charles. 2009. ‘The Use and Abuse of Scenarios’.
McKinsey & Company. November 2009. https://www.
mckinsey.com/business-functions/strategy-and-corporate-
nance/our-insights/the-use-and-abuse-of-scenarios.
Rozenberg, Julie, Cecilia M. Briceno-Garmendia, Xijie
Lu, Laura Bonzanigo, and Harry Edmund Moroz.
2017. ‘Improving the Resilience of Peru’s Road
Network to Climate Events’. WPS8013. The World
Bank. http://documents.worldbank.org/curated/
en/691821490628878185/Improving-the-resilience-of-
Perus-road-network-to-climate-events.
Rue, Simon, Jennifer Daron, Jennifer Copic, Éireann
Leverett, and Tamara Evan. 2018. ‘Submission to
UK Parliamentary Joint Committee on the National
Security Strategy: Cyber Security: Critical National
Infrastructure Inquiry’. UK Parliamentary Joint
Committee on the National Security Strategy. http://
data.parliament.uk/writtenevidence/committeeevidence.
svc/evidencedocument/national-security-strategy-
committee/cyber-security-critical-national-infrastructure/
written/81366.html.
Rumsfeld, Donald. 2002. ‘Press Conference US SoD’. NATO
HQ, Brussels, June 6. https://www.nato.int/docu/
speech/2002/s020606g.htm.
Sayers, Paul B., Gerald E. Galloway, and Jim W. Hall.
2012. ‘Robust Decision-Making under Uncertainty ?
Towards Adaptive and Resilient Flood Risk Management
Infrastructure’. In Flood Risk, 281–302. ICE Publishing.
https://doi.org/10.1680/fr.41561.281.
Schroeck, Michael, and Rebecca Shockely. 2012. ‘Analytics:
Real-World Use of Big Data in Insurance’. IBM. IBM
Institute for Business Value (blog). 2012. https://www.
ibm.com/services/us/gbs/thoughtleadership/big-data-
insurance/.
Schwartz, Peter. 1997. Art of the Long View: Planning for the
Future in an Uncertain World. New Ed edition. Chichester:
John Wiley & Sons.
Serinaldi, Francesco. 2015. ‘Dismissing Return Periods!’
Stochastic Environmental Research and Risk Assessment
29 (4): 1179–89. https://doi.org/10.1007/s00477-014-
0916-1.
Social Finance Inc. 2012. ‘Social Impact Bonds: An Overview’.
Social Finance. Boston, MA: The Rockefeller Foundation.
https://www.socialnance.org.uk/sites/default/les/
publications/small.socialnancewpsinglenal.pdf.
Star, Jonathan, Erika L. Rowland, Mary E. Black, Carolyn A. F.
Enquist, Gregg Garn, Catherine Hawkins Homan, Holly
Hartmann, Katharine L. Jacobs, Richard H. Moss, and
Anne M. Waple. 2016. ‘Supporting Adaptation Decisions
through Scenario Planning: Enabling the Eective
Use of Multiple Methods’. Climate Risk Management
13 (January): 88–94. https://doi.org/10.1016/j.
crm.2016.08.001.
The Economist. 2017. ‘A Lloyd’s Report Urges Insurers to Ask
“What If?”’ The Economist, 19 October 2017. https://www.
economist.com/nance-and-economics/2017/10/19/a-
lloyds-report-urges-insurers-to-ask-what-if.
Tourki, Yousra, Jerey Keisler, and Igor Linkov. 2013.
‘Scenario Analysis: A Review of Methods and Applications
for Engineering and Environmental Systems’.
Environment Systems & Decisions 33 (1): 3–20. https://
doi.org/10.1007/s10669-013-9437-6.
Tuck, Laura. 2016. ‘Embracing Uncertainty for Better
Decision-Making’. Text. Ppps. 3 October 2016. http://
blogs.worldbank.org/ppps/embracing-uncertainty-better-
decision-making.
Tversky, Amos, and Daniel Kahneman. 1974. ‘Judgment under
Uncertainty: Heuristics and Biases’. Science 185 (4157):
1124–31. https://doi.org/10.1126/science.185.4157.1124.
UNISDR. 2017. ‘Terminology on Disaster Risk Reduction’.
UN Oce for Disaster Risk Reduction. 2 February 2017.
https://www.unisdr.org/we/inform/terminology.
Valenzuela, Ana, and Priya Raghubir. 2009a. ‘Position-Based
Beliefs: The Center-Stage Eect’. Journal of Consumer
Psychology 19 (2): 185–96. https://doi.org/10.1016/j.
jcps.2009.02.011.
Van der Helm, Ruud. 2006. ‘Towards a Clarication of
Probability, Possibility and Plausibility: How Semantics
Could Help Futures Practice to Improve’. Foresight 8 (3):
17–27. https://doi.org/10.1108/14636680610668045.
Van der Merwe, Louis. 2008. ‘Scenario-Based Strategy
in Practice: A Framework’. Advances in Developing
Human Resources 10 (2): 216–39. https://doi.
org/10.1177/1523422307313321.
Van Notten, Philip W. F, Jan Rotmans, Marjolein B. A
van Asselt, and Dale S Rothman. 2003. ‘An Updated
Scenario Typology’. Futures 35 (5): 423–43. https://doi.
org/10.1016/S0016-3287(02)00090-3.
Van Vuuren, Detlef P., Marcel TJ Kok, Bastien Girod, Paul
L. Lucas, and Bert de Vries. 2012. ‘Scenarios in Global
Environmental Assessments: Key Characteristics and
Lessons for Future Use’. Global Environmental Change 22
(4): 884–95.
Vandenabeele, Tim. 2014. ‘Solvency II in a Nutshell’. Milliman.
http://nl.milliman.com/uploadedFiles/insight/2014/
solvency-ii-nutshell.pdf.
Zastrow, Mark. 2019. ‘Fukushima Bosses Cleared over Nuclear
Disaster’. Nature. https://doi.org/10.1038/d41586-019-
02822-y.
42
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