Stephen Richards
Articles written by Stephen Richards
Mortality crossover
Model selection
When fitting a mortality model, analysts are faced with the decision of which risk factors to include or exclude. One way of doing this is to look for the improvement in an information criterion that balances the fit against the number of parameters. The bigger the improvement in the information criterion, the more strongly the model with the smaller value is preferred.
Matrix repair
When fitting a statistical model we want two things as a minimum:
Mortality convergence
Seasonal mortality and age
The Hermite model of mortality
In Richards (2012) I compared seventeen different parametric models for modelling the mortality of a portfolio of UK annuitants. The best-fitting model, i.e. the one with the lowest AIC, was the Makeham-Beard model:
\[\mu_x = \frac{e^\epsilon+e^{\alpha+\beta x}}{1+e^{\alpha+\rho+\beta x}}\qquad(1)\]
Mortality down under
Is your mortality model frail enough?
Mortality at post-retirement ages has three apparent stages:
Compare and contrast: VaR v. CTE
New year, new insights
Happy New Year to all our readers!