Mortality Projection Model for Japan with Age-Shifting Structure

Futoshi Ishii, National Institute of Population and Social Security Research, Japan

In the latest Japanese official population projection in 2006 prepared by National Institute of Population and Social Security, new mortality projection model, which is a modified Lee-Carter model with age-shifting structure has been studied and used. Recent years, Japanese old age mortality has been improved remarkably. This model has been developed to adapt the situation. In this study, the structure and the projected result of the model will be described. New mortality projection model with age-shifting structure is a Lee-Carter model applied with the shift amount by “the shifting logistic model” proposed by Bongaarts(2005), noticing that we can recognize recent mortality curve changes in Japan as the shifting of curves in the direction of older people. Moreover, we have compared the age-shifting model with the Lee-Carter model. From the observation of relative level of mortality, higher performance of the age-shifting model is suggested.