Old-Age Mortality, the Maximum Life-Span and Their Influence on Variability of Death and the Rectangularization of the Survival Function

Marcus Ebeling, University of Rostock and Max Planck Institute for Demographic Research

Rectangularization — the development of an increasingly rectangular shape of the survival curve — has been theoretically predicted and empirically shown among humans in nearly all low mortality countries in the last decade. Due to the differing pace of improvement of old-age mortality and the maximum life-span, rectangularization need to be approached from a different perspective. Explanations that account for this relation, however, remain limited. We propose a new approach which enables an investigation of the dependency of both issues. The Maximized Inner Rectangle Approach (MIRA), which determines the biggest rectangle under the survival curve, allows a decomposition of life years lived and lost, thereby enabling an examination of the used and unused human living potential. Different old-age mortality modeling strategies are applied and evaluated to model the maximum life-span and explore the relationship between the degree of rectangularization and the developments at the end of life.