ABSTRACT
Traditionally we monitor inequalities in mortality by comparing mean outcomes between groups—for instance gaps in the life expectancy at birth or differences in age-standardized death rates. Overlooked in this approach are inequalities in mortality within groups, which are both substantial and changing over time. In this chapter, I argue for the importance of lifespan inequality (also known as age-at-death variation or lifespan variation) as a summary metric of mortality. I give an overview of the main ways it can be measured, describe its relationship to other summary measures of mortality and review the key empirical findings that have been conducted to date with this metric. I argue that a better integration of aggregate age patterns of mortality with life course theories would enrich both macro- and micro-level investigations.
