Chapter 15: Quantifying uncertainty in reserves Flashcards
9 Random factors influencing the run-off of claims reserves
- the OCCURRENCE and SEVERITY of claims
- levels of claims INFLATION
- changes in the mix of claim TYPES
- the notification DELAYS on individual claims
- changes in claims HANDLING
- legal changes that affect the size of awards
- legal changes that affect the “heads of damage” awarded
- court rulings on liability or quantum of individual claims not foreseen by claims handlers or not in the historic data
“Heads of damage”
Types of loss recognised in compensation awards for serious injuries, such as loss of income, medical and nursing costs, etc.
Awards due to:
- loss of income
- nursing costs
- pain and suffering
Further uncertainties in using historic data to project the run-off of claims (3)
- The historic data only provides a limited sample
- The quality of data may have varied over time.
- “model uncertainty”
4 Terms used to identify the sources of uncertainty
- Parameter uncertainty
- Process uncertainty
- Model error
- Systemic error
Process uncertainty
The uncertainty in what the future outcome will be.
This is the randomness of the underlying process.
Parameter uncertainty
The uncertainty in selecting parameters within the reserving process, and hence the results.
Model error
The error/uncertainty arising from the fact that we might select an inappropriate model to derive our reserve estimates.
Systemic error
The uncertainty arising from unforeseen trends or shifts away from the current claims environment.
3 Types of ranges that might be used
- range of best estimates
- range of possible outcomes
- range of reasonable / probable / plausible outcomes
“Range of possible outcomes”
This would represent the actuary’s estimate of the complete range of outcomes for future claims.
It would be considerably wider than the range of best estimates.
“Range of reasonable / probable / plausible outcomes”
This would typically be wider than a range of best estimates, but narrower than the range of possible outcomes,
… since it would allow for outcomes that cannot reasonably be regarded as an estimate of the mean or average outcome.
Stochastic claims reserving can be used to: (6)
- assess reserve adequacy
- compare different estimates and datasets
- monitor performance
- allocate capital
- provide information to investors
- facilitate discussions with regulators
2 Advantages of using the “Alternative sets of assumptions” method
- It is simple to perform on deterministic or stochastic models
- We use judgement when we select possible parameters. We can therefore allow for atypical volatility in the historical data.
3 Disadvantages of using the “Alternative sets of assumptions” method
- We assign no explicit probability to each set of parameters.
- We ignore model uncertainty using this method
- We do not allow for process uncertainty if we use alternative sets of assumptions for a deterministic model.
Scenario analysis
The likely impact of a CATASTROPHIC EVENT on a firm’s outstanding liabilities is measured.
Scenario analysis:
3 ways of deriving a scenario
- basing it on an historical event
- thinking up a hypothetical event using our judgement, or
- from the results of a stochastic model