Trends in Senescent Life Expectancy

John Bongaarts, Population Council

The distinction between senescent and non-senescent mortality has proven very valuable for describing and analyzing age patterns of death rates. Unfortunately, standard methods for estimating these mortality components are lacking. The first part of this study discusses alternative methods for estimating background and senescent mortality among adults and proposes a simple new approach. The second part examines trends in senescent life expectancy (i.e. the life expectancy implied by senescent mortality) and compares them with trends in conventional longevity indicators between 1960 and 2000, in a group of 19 developed countries with low mortality. Senescent life expectancy for females rose at an average rate of nearly 1.5 years per decade between 1960 and 2000, in these countries. The shape of the distribution of senescent deaths by age remained relatively invariant while the entire distribution shifted over time to higher ages as longevity rose.