Chapter 15 Models Flashcards

1
Q

What are the primary objectives of a health insurance model? (4)

A
  • enable an actuary working for a health insurer to give appropriate advice to run insurer in a finanially sound manner.
  • used in day-to-day work/running of company
  • provide checks and controls of business
  • judgment will be required on choosing model type and selection of inputs/assumptions.
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2
Q

Main uses of models (9)

A
  • model office
    • new business projections
    • embedded value
    • solvency
    • takeovers
  • pricing
    • profit premium rates
  • reserves
  • costing and reserving for options
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3
Q

List the 4 different types of insurance company models (that differ in the policies that are included in the model).

Briefly descibe what each model does

(12)

A
  1. Profit testing model
    • projects expected cash and profit flows on policies from date of issue
    • key for pricing/product design
      1. New business model
    • projects all expected cash and profit flows arising from future sales of new business
    • useful for assessing future capital requirements for new business/overall return on capital achieved from future sales
      1. Existing business model
    • cash & profit flor projection from all existing business company has in force at particular time point
    • important for assessing intrinsic value of existing business and testing solvency of company’s existing business
      1. Full model office
    • sum of new and existing business model
    • of fundamental importance in assessing impact of future maangement decisions on company’s future financial development
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4
Q

The main types of insurance models will either be used for

  • profit testing/pricing
  • new business modelling
  • existing business modelling
  • full model office

List the basic ‘building block models’ that each of these broader model types will require? (3)

A
  • Policy liability model
  • Expense model
  • Asset model
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5
Q

Building blocks of different model types: in depth

Describe what we mean by the following ‘model building blocks’:

policy liability model (8)

expense model (2)

asset model (5)

A

Policy liability model

  • projects cashflows
    • can use standard software package
    • should tailor to insurer’s product range (product types, charging structure, surrender values, options, model points)
  • projects foward the in-force book of policies, depending on
    • existing business, new business, transitions, lapses, renewals
  • also requires total policy cashflows

Expense model

  • used for build-up of total expenses
  • fixed overheads may be modelled globally rather than summing up per-policy loadings

Asset model: varies in complexity depending on purpose of model

  • for profit testing:
    • often only future annual expected investment return
  • for full model office:
    • likely consider investment strategy with stochastic asset model…
    • …considering individual asset returns and distribution for each class
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6
Q

State the requirements of a good model (14)

A
  1. Valid for purpose
    • deterministic vs stochastic
    • includes all notable features of what is being modelled
  2. Rigorous
    • realistic results under wide range of circumstances
  3. Well documented
    • audit trail, key assumptions/approximation
  4. Components used allow for material aspects being modelled
    • structural components:
    • parameters: only include param if results differs for different values of the parameter
  5. Parameter values appropriate
    • for particular business
    • general environment, account for special features of company/economic environ
  6. Reflect risks being modelled
  7. Sensible joing behaviour of variables eg:
    1. higher expense inflation => higher claims inflation
    2. higher claims rates => higher reinsurance recoveries
    3. higher inflation => higher (nominal) bond yields, equity returns?
  8. Dynamic: assets and liabilities
    1. assumptions used to model assets/liabitlies must be consistent
    2. interactions between assets/liabilities modelled
  9. Easy to
    1. Understand/appreciate model
    2. Communicate model
  10. Output reasonable able to independent verify reaonableness
    1. Reconcile with supervisory valuation
    2. Reconcile with results from last run
    3. Ratio checks on future results
    4. Back of the envelope model
  11. Output communicable
    1. to those who advice will be given to
    2. mentioning underlying method, critical assumptions
  12. Results displayed clearly
  13. Not overly complex to
    1. understand
    2. explain/communicate
    3. expensive to run
  14. Able to develop/refine over time
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7
Q

List the specific/basic features of a health insurance model

(7)

A
  • Projecting all cashflows that may arise and profit
    • Allowance for supervisory reserves
    • Allowance for solvency margin
  • Multiple state modelling
  • Allow for interactions/corellations between variables (dynamic links; joint sensible behaviour)
  • Guarantees/options should be appropriately allowed for (typically using stochastic modelling)
  • Use of suitable projection frequency/time period
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8
Q

Features of a health insurance model:

  • Projecting cashflows/profit (15)
A

Projecting cashflows/profit

  1. model must allow for all cashflows that may arise
    • depends on contract’s nature, premium, benefit structure, discretionary benefits, options, renewal without further evidence
      1. supervisory reserves (allow for cashflows arising from supervisory need to hold reserves/solvency capital)
    • increase in reserves is a contribution from free assets/negative cash flow and vice versa
    • real cashflows
      • premiums, investment income, payments to policyholders, commission to agents, expenses, tax
    • notional cashflows
      • fund establishment of reserves, by contributing money to reserves from cashflow or initially from company’s free assets
      • this increase in reserves is negative from company’s perspective
      • at maturity/claim, reserves will be released to help pay appropriate benefit => decrease in reserves positive
        1. supervisory solvency capital
    • in addition to supervisory reserve, might be minimum supervisory solvency capital requirement to cover.
    • policy cashflow might also need to fund establishment of solvency margin.
    • increase in solvency margin is negative cash flow and vice versa
    • required solvency margin included in value of reserves
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9
Q

Health insurance model: real vs notional cashflows, projecting cashflows/profit

What do we mean by ‘real cashflows’ vs ‘notional cashflows’ when modelling? (2)

Give examples of ‘real cashflows’

Give examples of ‘notional cashflows’

A

Real vs notional cashflows

  • cashflows in the modelling exercise may either be real or notional
  • for notional cashflows, there’s no ‘real exchange’ of funds which would occur in the real world t mimicl the cashflow in question

Real cashflows

  • positive: premium income, investment returns
  • negative: benefit payments, distribution remuneration, expenses, tax

Nomial cashflows

  • positive: decrease in reserves/capital required
  • negative: increase in reserves/capital required
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10
Q

Features of a health insurance model: multiple state modelling

Describe how this feeds into health insurance models (3)

A

Multiple State Modelling: for healthcare, need to project separately cash flows arising from different states, and reflect state transitions.

  • healthy, incapacitated and not receiving benefits, and receiving benefits (by benefit level, if appropriate)
  • used mainly for LTCI; cash flows depend on state.
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11
Q

Features of a health insurance model:

  • allowing for interactions (2,5)
A

Cashflows need to allow for any interactions, particularly where assets and liabilities are being modelled together.

Dymaic model (asset/liability parts programmed to interact as in real life e.g.

  • supervisory reserves consistent with projected investment conditions and company’s investment strategy, depending on current marketing conditions (e.g. conservative when financial position is poor)

Links are important

  • for all models, but
  • particularly for stochastic models, as variables are changing yearly and ongoing response need to occur automatically as each simulation is run
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12
Q

Features of a health insurance model:

  • allowance for guarantees/options (3)
A

Where health options exist (e.g. option to effect a new term assurance contract without providing further evidence of health), the potential cashflows from such options need to be allowed for:

  • Allow for effect on supervisory reserves
  • Allow for stochastic models/simulations
    • …where appropriate, in order to assess impact of financial guarantees (e.g. minimum maturity guarantees)
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13
Q

Features of a health insurance model:

Frequency (3)

Period (5)

A
  • Frequency
    • more frequent cashflows calculation => more reliable output
    • less frequent cashflow calculation faster model is run
    • usually monthly
  • Period
    • Whole company models
      • projection period chosen normally 3…5 years
      • anything more expose to doubt, especially regarding level and mix of new business,
      • but may usefully indicate significant trends, especially regarding solvency.
    • Individual product cashflows for profit testing purposes:
      • the projection period used will be the policy term.
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14
Q

Model points

What is a model point (MP)? (3)

How do model points help in the modelling exercise? (2)

What is the most important thing to remember when choosing model points? (2)

A

MP is a

  • data record fed as input into a model/modelling programme as inputs for existing business or new business…
  • …will represent either a single policy or group of homogenous policies and their most important attributes
  • …will contain most important characteristics of the policy

How model points help?

  • underlying business comprises wide range of pols
  • MPs group policies expected to produce similar results, which can then be scaled up, saving time, requiring less power

Most important thing about model points

  • above all, MPs should be chosen so that they reflect adequately the distribution of business being modelled
  • starting point will often be MPs used during previous iteration of this exercise, but this has been changing to ‘create new MPs’ each time due to increased computing power
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15
Q

Model points:

Choosing model points

In force business (3)

A

In force business

  • above all, MPs should be chosen so that they reflect adequately the distribution of business being modelled
  • group pols of same prod type which share acceptably similar characteristics, which will then contain average value for premiums, benefit guaranteed, etc
  • group data to fit within computer constraints
  • check validity: for block of pols=> compare grouped/ungrouped results
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16
Q

Model points:

Choosing model points

New business (3)

A

New business, consider

  • above all, MPs should be chosen so that they reflect adequately the distribution of business being modelled
  • Look at
    • new business production
    • trends in new business pols
    • marketing changes
    • planned new product launches
    • imminent legislative/fiscal changes
  • Influence on sales/persistency (for life and health care products)
    • economic morale
    • government provision of welfare
    • tax
    • political commitment (government offering alternatives)
  • Business volumes
  • Business mix
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17
Q

Modelling process: deterministic vs stochastic, key features

List the key features of the deterministic modelling process (3)

List the key features of the stochastic modelling process (3)

A

Key features of deterministic modelling process

  • each parameter has a fixed value
  • the model produces point estimates for the results
  • possible to sensitivity test the results by running model and varying the parameter values

Key features of stochastic modelling process

  • some parameters can vary and/or have their own statistical distribution
  • stochastic model must be run many times using random samples of the distribution functions
  • model produces results in the form of a probability distribution
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18
Q

Why is stochastic modelling more important for health insurance than for pure life insurance?

A
  • for health and care, future experience/incidence ratio is far less easier to predict than for life insurance contracts
  • the difficulty lies in the potential benefit amount, which may vary by
    • policy-specified inflation (LTCI)
    • medical inflation, (PMI),
    • changes in accepted medical practices/protocols (PMI),
    • …and other factors
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19
Q

State 5 advantages of deterministic models compared to stochastic models (5)

A
  1. Easier to explain (particularly to non-technical audience)
  2. Easier to interpret/understand
  3. Clearer which (economic) scenarios have been tested
  4. Easier to design
  5. Easier/shorter to run
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20
Q

Give examples of circumstances in which deterministic models might be appropriate (4)

A
  1. If similar results possible as if stochastic projection were used.
    • Possible outcomes form a symmetric distribution/information and information only required on the expectation, or
    • specific scenario being tested within simple cashflow model
  2. Quick, independent test is required to see that the results of a stochastic projection are reasonable
  3. To provide upper and lower bounds
  4. To avoid nested stochastic model
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21
Q

For stochastic models compared to deterministic models:

  • State 3 advantages (3)
  • State 2 disadvantages (2)
A

Advantages

  1. Distribution of outcomes (not just single outcome) because can prob distribution to one/more unknown future parameters
  2. Positive liability can be calculated where deterministic approach might otherwise produce zero liability e.g. costing options and guarantees
  3. Interactions explicitly modelled i.e parameters may be assumed to vary together

Disadvantages

  1. Time and computing constraints
  2. Possible spurous accuracy i.e. results very senstitive to (deterministically chosen) assumed values of parameter(s) involved….rubbish in => rubbish out, lol ! )
22
Q

Choosing between stochastic and deterministic model

Decsribe the approach that might be taken in order to make a choice between stochastic modelling vs deterministic modelling (7)

What can stochastic modelling be highly useful for (which would drive the question as to whether to model stochastically, or determinstically) (4)

A

Approach for choosing stochastic vs deterministic modelling

  • determine if stochastic approach is desirable or necessary
    • eg with options/guarantees;
    • if it is, then use stochastic, else use deterministic
  • determine if future probability distribution can be specified with good degree of confidence; consider:
    • past data,
    • fit of model to data,
    • what factors are significant in future

Stochastic model can be invaluable for:

  • assessing stochastic impact of guarantees
  • variable of interest is predicablte and has is reasonably stable/has reasonably stable probability distribution
  • indicating the effect of year-on-year volatility on risk
  • identifying potentially high-risk future scenarios
23
Q

Describe 2 approaches to calibrating stochastic models of economic variables

(5)

(4)

A

Risk neutral/market-consistent

  • market-consistent: typically used for valuation purposes, particularly where there are options/guarantees
  • focus: attempt to replicate market prices of financial instruments as closely as possible using risk neutral probability measure
    • choose number of financial instruments for which price is known
    • build model than can project cashflows from these instruments in a range of scenarios
    • parameters are chosen such that average PV of cashflows from modelled simulations is sufficiently close to known market price

Real world calibrations

  • typically used for projecting in future e.g. for calculating appropriate level of capital to hold to ensure solvency under extreme adverse future scenarios at a given confidence level
  • focus: use assumptions according to realistic ‘long-term’ expectations and which consequently also reflect onbservable real world probabilities/outcomes
    • determine model parameters using expectations of future
    • assumptions used to project the values of assets/liabilities under each stochastic scenario
24
Q

Equation of value approach

What does this approach entail? (5)

A
  • Also known as the formula approach
  • Setting an equation of value, through which we solve for an unknown value, usually the premium
  • Will typically be the ratio of 2 values
    • Premium = numerator /denominator
    • Numerator: Value of outgo less Value of non-premium income (investment yields)
    • Denominator: Value of 1 unit monthly/single premium
  • The above values would be discounted using suitable interest rate equivalent to the return achievable by investing the proceeds of policy.
    *
25
Q

Equation of value approach: premiums

When using the equation of value approach, what would the value of premiums include? (2)

A
  • value of 1 unit of premium income projected and discounted, allowing for escalation, persistency rates and waivers
  • expenses including commission which relate to premium size would be included here.
26
Q

Equation of value approach: claims

When using the equation of value approach, what would the value of claims include? (3)

A
  • value of claims discounted for all future claims outgo over policy duration
  • claims handling expenses
  • inflation assumptions on claims and expenses
27
Q

Equation of value approach: expenses

When using the equation of value approach, what would the value of expenses include? (2)

A
  • expenses not directly related to claims or premiums
  • appropriate inflation will apply
28
Q

Equation of value approach: investment income

When using the equation of value approach, how is investment income included? (5)

A
  • cost of reserves is ignored in this method
  • it could however be included by use of a cashflow/value which would
    • allow for timing differences between items bein received by company during the year against annual outgo,
    • with balance invested to year-end prior to being distributed
  • rather than including an explicit cashflow for investment income we adjust the discount factors used for other cashflows
29
Q

Equation of value approach: tax and other outgo

When using the equation of value approach, how would we allow for tax and other outgo? (2)

A
  • this can be allowed by using an adjsted the discount rate.
  • although explicit adjustments may be made on expenses or proftit
30
Q

Equation of value approach: profit transfer to insurer

When using the equation of value approach, how would we allow for the profit transfer to the insurer? (1)

A
  • formula can be altered to include specific profit objective.
31
Q

Equation of value approach: drawbacks

Discuss the advantages of using the equation of value/formula approach (2)

Discuss the disadvantages of using the equation of value/formula approach (6)

A

Advantages

  • considerable attraction in simplicity
  • still useful for pricing short-term contracts.

Disadvantages; does not allow for:

  • appropriate timing of events
  • accumulation of reserves
  • capital needs (properly)
  • impact of negative cashflows in any period
  • an individual to inspect the premium-related or claims related cashflows seperately
  • easily for variation of assumptions over time
32
Q

Cashflow approach: intro

Why was the cashflow approach developed? (3)

A
  • developed to overcome drawbacks of the formula approach
  • software packages handle both premium calculations and reserve setting
  • for products with options and guarantees, cashflow method may be better to use
33
Q

Cashflow approach: process

Describe the process of using the cashflow approach to modelling (10)

A
  • a number of model points will be chosen to represent expected new business under product.
    • in case of existing business model points will be adjusted for any expected changes in future
  • for each model point cashflows will be projected allowing for reserving, solvency capital requirements
  • the net cashflow may be investigated for the possibility of negative flows hence potential for additional reserve
  • net cashflows will then be discounted at a rate of interest, the risk discount rate
  • discount rate allows for:
    • return required, level of statistical risk of cashflows
    • in theory discount rate should vary by cashflow
  • net cashflows will be analysed to assess the adequacy of premium to product a desired return
  • actuary may on particular model points fine-tune calcs to produce desired profits
    • or focus at an overall level without requiring every model point to be profitable
  • once acceptable premiums have been achieved for model points, then premiums for all other contractss can be determined
34
Q

Cashflow approach: conventional without profit, typical cashflow elements

List the typical elements that conventional without profits business will include under a cashflow modelling approach (9)

A
  • premiums
  • claims
  • expenses
  • commission
  • contribution to reserves
  • contribution to capital requirements
  • interest on cashflows
  • tax
  • allowance for lapses, premium holidays, benefit level changes on long-term products.
35
Q

Cashflow approach: use in pricing

Broadly speaking, how might the cashflow approach to pricing work for PMI contracts? (3)

A
  • PMI incurrs higher costs when sold compared to renewal costs.
  • It may be appropriate to spread the initial cost over the expected number of renewals.
  • Once a premium structure has been established for short-term policies, cashflow projections may be used to assess the adequacy of these premiums over a longer term.
36
Q

Cashflow approach: to assessing profitability process

Describe how the cashflow approach may be used to assess the profitability of the insurer (7)

A
  • full policy data set may be used
  • alternatively model points may be used to represent the existing book.
  • the suitability of model points should be checked.
    • where the assessment of profitability is at the same time as when the supervisory reserves are calculated…
    • ….one check would be to use model points to determine the supervisory reserve and compare this to the published value.
  • for each policy present value of cashflows should be determined using an appropriate discount rate.
  • total across all policies (after scaling up) will give the expected profit from existing business.
37
Q

Use of cashflow approach in assessing profitability

When using a cashflow approach to assess profitability of the insurer, according to which different splits/categories may be useful to analyse the results? (8)

A

It can be useful to look at profitability by:

  • product
  • product class eg
    • short-term vs long-term,
    • group vs individual.
  • by distribution channel
  • by subsidiaries
  • part of calculating embedded value of an insurer
    • performing this will alert the insurer if any products need to be repriced
38
Q

Cashflow approach: determining capital requirements

Briefly describe the cashflow approach to determining capital requirements (3)

A
  • net cashflows in respect of model points, scaled up for expected new business under product…
  • …will be incorporated into a model of the business as a whole (often called model office)
  • the actuary can then assess the impact in capital management terms of writing the product, by observing model amount and timing of cashflows
39
Q

Cashflow approach: assessing RoE

Describe the process of using the cashflow approach to assessing the return on equity (RoE) (7)

A
  • cashflows produced for model points can be grossed up for the expected new business or existing business and used to assess amount of capital needed to write the product.
  • basis can either be
    • regulatory or economic
  • this calc can should also be adjusted to allow for development costs to the extent that they have not already been amortised/included in expense CFs used
  • the above calc would give total capital requirement…
  • ….which can be compared to profits expected to emerge from products to determine expected RoE.
40
Q

Multi-state modelling: intro

What is multi-state modelling? (4)

What are the various states that lives may exist in when incorporated into a multiple state model? (6)

A

Intro

  • used where policyholders can exist in differenct states each with a different set of cashflows
  • in health and care insurance context, applies to
    • LTCI…
    • ….where a claim does not terminate the policy

Potential states: policyholders are separately tracked through the various stages of capability and claiming as follows:

  1. capable premium payers
  2. incapacitated within deferred period
  3. lives becoming claimants following deferred period
  4. lives moving to further stages of incapacity
  5. lives recovering, reverting to premium payers
  6. lives dying
41
Q

Multi-state modelling: pricing

Describe how multiple state modelling may be used in pricing of health and care insurance contracts (6)

A
  • pricing using this approach requires proportions of lives in each state
  • the value of claims outgo depends on the numberr of lives within benefit paying cohorts
  • this will be balanced against the premium income received from those in premium paying states, plus investment income less any expenses.
  • transition intensities will be applied to determine proportions in each state for the next month
  • this model could be very complex due to the number of open states
  • however in practice cohorts/subgroups may be grouped .
42
Q

Multi-state modelling: reserving/reporting purposes

Describe how multi-state modelling may be used for reseriving/reporting purposes (4)

A
  • a similar approach will be taken as for multi-state modelling used in pricing
  • however, assumptions used in calculating reserves for statutory purposes may be different
    • from those used in assessing the liabilities that are transferred on the sale of a company, and
    • for pricing
  • thus assumptions used in transition intensities will vary according to the overall purpose of the analysis
43
Q

What are the different sensitivities to consider testing during the modelling process? (5)

A

Sensitivity of model to:

  • the choice of model points
  • parameters
    • when pricing
    • when reserving
    • when assessing return on capital/profitability
44
Q

Sensitivity testing: model points

Describe the logic behind sensitivity testing model results in terms of choice of model points (4)

A
  • When enough number of representative model points are used in modelling, it isnt necessary to perform this sensitivity test.
  • However if a less than ideal number of model points have been be used then it is worth assessing the sensitivity of this. i.e test effect of different choice of model points.
45
Q

Sensitivity testing: sensitivity due to choice of parameters

Discuss how/why we may want to sensitivity test model results considering choice of parameters (3)

Why is sensitivity testing useful? (5)

Give examples of different exercises for which we may subject the choice of parameters to sensitivity testing (3)

A

In terms of parameters, we’d want to sensitivity test the effect of parameter mis-estimation on results

  • the effect of parameter mis-estimation can be assessed by varying parameter values and observing impact of model results.
  • when doing this any correlation between parameters must be allowed for.

Sensitivity testing is useful

  • to determine effect of divergeance in actual future experience from expected
  • to give a range of where best-estimate lies + reflect which parameters are most significant (ie impact results most)
  • to compare relative financial impact of parameters’ uncertainty, so that insurer may
    • design products which are robust to certain parameters that are highly uncertain, or
    • may include higher margins where necessary (while keeping price in mind)

We may sensitivity test parameters used in

  • pricing
  • reserving
  • assessing return on equity/profitability
46
Q

Sensitivity testing: parameters, pricing

In what way is sensitivity testing of parameters useful when pricing? (4)

A
  • allows us to assess what margins need to be incorporated into the parameter values.
    • eg if current investment yield is 6% but insurer expects this to drop and produce unreasonable results then the insurer might consider dropping the yield to 4%.
  • useful as a qualitative check in order to obtain acceptable results
  • useful to see which parameter(s) the price is sensitive to
    • may need to redesign product
47
Q

Sensitivity testing: parameters, when reserving

In what way is sensitivity testing of parameters useful when reserving? (8)

A
  • to determine margins needed to ensure assumptions in reserves are prudent/enough to meet liabilities
  • to assess the extent to which additional margins to reserves are needed
  • to determine global contingency reserves, which might be needed to protect company from:
    • asset crash
    • excessive death or sickness
    • mismatch between assets and liabilities
    • selective exercise of policyholder options
48
Q

Sensitivity testing: parameters, when assessing RoE/profitability

In what way is sensitivity testing of parameters useful when assessing RoE (return on equity) /profitability? (5)

A
  • enable actuary to quantify effect of departures from chosen parameter values
  • help determine variance of profit, or of the return on capital for any business being modelled
    • stochastic techniques can also be used
    • where a distribution exists for a parameter then a variance will be produced of the profit/RoE
    • sensitivity/scenario analysis can be performed at a certain confidence intervals of the distribution
49
Q

Sensitivity testing: sensitivity due to choice of parameters

With regards to parameters used, what is the difference between sensitivity testing and scenario testing? (2)

A

Sensitivity testing of parameters

  • varying parameters one by one to understand their impact on results (but also allowing for correlation which may exist between given parameters, as these can’t be ignored)

Scenario testing

  • essentially sensitivity testing where many parameters are adjusted in a consistent way at the same time, so as to, in effect, understand the impact of a given scenario
50
Q

Sensitivity testing: allowing for risk, intro

What are 3 different ways of allowing for risks that may be identified during the sensitivity testing process? (3)

A
  1. Allowing for statistical risk
  2. Quantify effect of departures from chosen parameter values
  3. Stochastic modelling
51
Q

Sensitivity testing: allowing for risk, expand

Describe what we mean by each of the following ways of allowing for risk in the sensitivity testing process

Allowing for risk statistically (2)

Quantifying effect of departures from chosen parameter values (4)

Stochastic modelling (4)

A

Statistical risk

  • adjusting risk element of RDR
  • pre-determined lower RDR wiith assessment of effect on results of models of statistical risk

Quantify effect of departures from chosen parameter values

  • assign probability distribution: allows derivation of variance of profit or ROC analytically (prob distri difficult to assign)
  • sensitivity analysis
  • monte carlo simulation: assess variance of profit using stochastic model for distribution of parameter

Stochastic model

  • assess impact of options/guarantees
  • if variable has stable/predictable probability distribution
  • indicate effect of year on year volatility risk
  • identify high risk future scenarios