Mortality plateau - the Gamma-Gompertz and other plausible mixture models

Trifon I. Missov, Max Planck Institute for Demographic Research

Statistical analysis of data on supercentenarians revealed that the human force of mortality is flat after age 110. This implies that either human mortality levels off or it abandons the observed plateau after a certain age. We consider a general model introduced by Finkelstein and Esaulova (2006) which represents a mixture of a baseline failure distribution and a mixing (frailty) distribution that accounts for unobserved heterogeneity among individuals. In this article we describe under certain assumptions a class of frailty distributions that implies the asymptotic behavior of the mixture hazard rate of this general model.