(May 2006) After remaining fairly constant for most of human history, life expectancy (the average number of years a person can expect to live) has nearly doubled in the past century. The maximum life span—the longest number of years a human being has lived—has increased spectacularly as well. Scholarly opinion diverges, however, as to whether these increases will continue or whether human longevity is approaching its limit.

In 1990, the Behavioral and Social Research (BSR) Program of the National Institute on Aging (NIA) began sponsoring academic centers for research on the demography of aging. Support for this type of research is increasingly important, since improved projections of life expectancy—which give us some idea of the future size of the elderly population—are key in informed planning for the allocation of public and private resources.

The Future of Human Life Expectancy, a new policy brief by the Population Reference Bureau and BSR, highlights some of this research. Written by Amanda Sonnega, associate director for external relations at the Michigan Retirement Center, University of Michigan, the brief discusses the latest scholarly thinking on how best to project life expectancy, given trends such as the recent decline in disability rates and rise in childhood obesity. The brief is one in a series entitled “Research Highlights in the Demography and Economics of Aging.”