Dynamics of life expectancy and life span equality
A unifying framework is developed to study life expectancy and life span equality over time, relying on concepts about the pace and shape of aging, to demonstrate that both changes in life expectancyand life span Equality are weighted totals of rates of progress in reducing mortality.
Abstract
<jats:title>Significance</jats:title> <jats:p>Why life expectancy and life span equality have increased together is a question of scientific interest. Both measures are calculated for a calendar year and might not describe a cohort’s actual life course. Nonetheless, life expectancy provides a useful measure of average life spans, and life span equality gives insights into uncertainty about age at death. We show how patterns of change in life expectancy and life span equality are described by trajectories of mortality improvements over age and time. The strength of the relationship between life expectancy and life span equality is not coincidental but rather a result of progress in saving lives at specific ages: the more lives saved at the youngest ages, the stronger the relationship is.</jats:p>