As the world goes through the demographic transition, the distribution of the world population has changed from larger proportions in the younger age groups, to intermediary higher proportions in the working age groups, to final increasing proportions in the older age groups. However, across the globe, the demographic transition has varied with respect to the onset, pace, and scale of mortality and fertility declines, leading to different processes of population aging. Although earlier studies have looked at population aging in various contexts, the international literature lacks a systematic comparative analysis of the demographic determinants of population aging. We examine the contribution of births, deaths, and migrations to population aging in the world from 1950–1955 to 2095–2100. We decompose the rate of change in the mean age of a population, and propose a categorization of the stages of the demographic transition based on the demographic determinants of population aging.
Presented in Session 64. Cross-National Comparisons in Aging