At What Age Does Mortality Start to Decelerate?

Roland Rau, Max Planck Institute for Demographic Research
Magdalena Muszynska, Duke University
Annette Baudisch, Max Planck Institute for Demographic Research

Throughout most of the adult lifespan, mortality increases linearly on a logarithmic scale. At advanced ages, though, mortality levels often result in overestimating mortality if a Gompertzian shape is assumed. Most commonly this mortality deceleration is measured by the life-table aging rate, introduced by Horiuchi and colleagues, but also other methods that were used previously. In this paper we present two alternative approaches to determine the age when mortality deceleration starts: (1) the age when mortality acceleration is at its maximum, and (2) the age when observed mortality deviates significantly from the exponential increase. After a theoretical justification, we show with empirical data that these two new methods are not only intuitively but also practically appealing. In a concluding empirical case study, we show that one of these new methods is well suited to detect trends in mortality deceleration over time.