Free SOA Exam ASTAM (Advanced Short-Term Actuarial Mathematics) Severity Models Practice Questions
Severity models on SOA Exam ASTAM cover parametric loss distributions (Pareto, lognormal, Weibull), tail behavior analysis, mixture distributions, and transformations used to fit insurance claim data.
Sample Questions
If , then the mean of is:
With and :
Tail classification by hazard rate behavior:
- Increasing hazard rate (IHR): lighter than exponential — tail decays faster than for some .
- Constant hazard rate: exponential distribution — light-tailed, with MGF defined for .
- Decreasing hazard rate (DHR): heavier than exponential — survival function decays slower than any pure exponential.
The exponential sits at the boundary between IHR (lighter) and DHR (heavier) distributions. It is classified as light-tailed because its MGF exists in a neighborhood of zero.
For the lognormal with parameters and , define . The mean excess loss at is: , where . With , , : . . , . . .