Marshall Flashcards
Risk Margin For Normal and Lognormal Distribution
Normal
* Z * CoV
* norminv(%-tile,0,CoV)
Lognormal
* Var = σ^2 = ln(1 + CoV^2)
* Risk margin = exp(-Var/2 + Z * SD) - 1
Independent Risk
What are they?
Parameter risk - randomness associated with the insurance process, makes it difficult to select appropriate parameters
Process risk - pure randomness associated with the insurance process
Internal Systemic Risk
Specification Error
What is it + good indicators
Impossible to build a model that is fully representative of the insurance process
* Many different models used
* Model separately analyses different claim/payment types (ideally homogenous groups modeled separately)
* Little variation in range of results produced by model
* Checks made on reasonability of results (business leader acceptance, expert peer review, reconcilate changes in liabilities, diagnostic checks on outcomes, benchmark against industry data)
* Subjective adjustments to factors (fewer the better)
* Detects trends in claim cost
* Detailed analysis and quantify superimposed inflation (legislative changes, things that increase claim cost but not real inflation)
* Detailed expense analysis
* Ability to model using more granular data, like claim level data
Internal Systemic Risk
Parameter Selection Error
What is it + good indicators
It’s impossible to pick all the right parameters (but we can get close)
* Best predictors (may or may not be used in model) with strong correlation to claim cost have been identified and analyzed
* Best predictors are stable over time or change due to process changes (not b/c they’re unstable)
* Modeled value of predictors used rather than subjectively selected, and lead claim cost outcome rather than lag (inflation predictor up –> claim cost up rather than claim cost up –> inflation predictor up)
Internal Systemic Risk
Data Error
What is it + good indicators
Poor data, unavailable data, and/or inadequate knowledge of the data
* Credible knowledge of past processes and changes in processes that affects predictors
* Consistent and reliable information from business (proactive 2-way communication with claims staff, underwriters, etc)
* Data is reocnciled against other sources and against prior analysis with differences explained
* Robust and replicable process for obtaining data (no or low potential for miscoding, etc)
* Ideally no prior instants of data revisions. But if there is, understand how frequent and how severe
* Ideally no known/current data issues. But if there is, understand possible impacts on predictions
External Systemic Risk
Examples
- Economic and social risks (inflation, unemployment, interest rates, etc)
- Superimposed inflation (legislative changes, courrt rulings)
- Changes in claims reporting/payment patterns, case reserve estimation process, etc
- Expense risk from policy maintenance and claim handling
- Event risk - a single event which triggers a large number of claims (ex. catastrophe)
- Recovery risk - reinsurance, S&S recoveries
Correlation Effects
Independent, Internal systemic, External systemic
Independent Risk
* Assumed to be uncorrelated with any other source of uncertainty/risk
Internal Systemic Risk
* Uncorrelated with the other 2
* May have some correlation between classes and/or liabilities (same actuary estimating liabilities across classes, likely a linkage between premium liability and reserve methods)
External Systemic Risk
* Uncorrelated with the other 2
* May have some correlation between classes and/or liabilities