Integrating Financial and Demographic Longevity Risk Models: An Australian Model for Financial Applications

Since its introduction, the Lee Carter model has been widely adopted as a means of modelling the distribution of projected mortality rates. Increasingly attention is being placed on alternative models and, importantly in the financial and actuarial literature, on models suited to risk management and pricing. Financial economic approaches based on term structure models provide a framework for embedding longevity models into a pricing and risk management framework. They can include traditional actuarial models for the force of mortality as well as multiple risk factor models. The paper develops a stochastic longevity model suitable for financial pricing and risk management applications based on Australian population mortality rates from 1971-2004 for ages 50-99. The model allows for expected changes arising from age and cohort effects and includes multiple stochastic risk factors. The model captures age and time effects and allows for age dependence in the stochastic factors driving longevity improvements. The model provides a good fit to historical data capturing the stochastic trends in mortality improvement at different ages and across time as well as the multivariate dependence structure across ages.