DISCUSSION PAPER PI-0803
Backtesting Stochastic Mortality Models: An Ex Post Evaluation of Multiperiod-Ahead Density Forecasts
Kevin Dowd, Andrew J.G. Cairns, David Blake, Guy D. Coughlan, David Epstein, and Marwa Khalaf-Allah
This study sets out a backtesting framework applicable to the multiperiod-ahead
forecasts from stochastic mortality models and uses it to evaluate the forecasting
performance of six different stochastic mortality models applied to English
& Welsh male mortality data. The models considered are the following:
Lee-Carter’s 1992 one-factor model; a version of Renshaw-Haberman’s
2006 extension of the Lee-Carter model to allow for a cohort effect; the age-period-cohort
model, which is a simplified version of Renshaw-Haberman; Cairns, Blake, and
Dowd’s 2006 two-factor model; and two generalized versions of the last
named with an added cohort effect. For the data set used herein, the results
from applying this methodology suggest that the models perform adequately
by most backtests and that prediction intervals that incorporate parameter
uncertainty are wider than those that do not. We also find little difference
between the performances of five of the models, but the remaining model shows
considerable forecast instability.
