Why Nations Become Wealthy: The Effects of Adult Longevity on Saving

Abstract

Many countries experienced a rema rkable increase in life expectancy during the 20th century, but the development implications have received only modest attention. We analyze steady state and out-of-steady-state effects of the transition in adult longevity on the national saving rate using an overlapping generations model. We show that the national saving rate depends on both the level and rate of change in adult survival. Countries with rapid transitions have particularly elevated saving rates. Empirical evidence is drawn from two sources: long-term historical trends for a small number of countries and world panel data for 1960-95. Two important conclusions are supported by the empirical analysis. First, the demographic transition had a large positive effect on aggregate saving, but over three-quarters of the gain was due to improvements in old-age survival rather than declines in youth dependency. Second, population aging will not lead to a decline in aggregate saving rates. The compositional effect – lower saving rates among the elderly – is dominated by the behavioral effect – individuals will save more to provide for a longer old age.