Length of Life Inequality Around the Globe: Within and Between Country Differences Disclosed and Decomposed

In this study, we address three basic questions about the degree to which length of life is distributed (un)equally within and among societies: (1) How large is overall inequality in length of life around the globe? (2) To what extent is this inequality caused by betweencountry differences and to what extent by within-country differences? (3) How is length of life inequality (LLI) related to life expectancy (LE)? To answer these questions, we first determine LE and LLI for the total adult world population in 2000 and decompose total world LLI into within and between country and geo-political region components. This analysis shows that most LLI (between 83 and 86 percent) is within country inequality. Next, we study the pattern of association between LE and LLI on the basis of a new database containing 9,053 life tables for 212 countries, covering a period of up to two centuries. The data reveal huge variation among countries and time periods in the degree to which the available years of life are distributed equally among the population. At similar levels of LE, mortality in the 15-50 age group may be 35 to 70 percent higher in the most unequal countries compared to the most equal ones. These findings make clear that not LLI as such, but LLI corrected for LE or relative length o f life inequality (RLLI) is the most relevant indicator of length of life differentials within populations. Analyses of trends within countries show that countries that reached a certain LE earlier in time and countries that improved their LE more quickly experienced higher levels of RLLI.