After a brief review of the controversy about future trends, this Population Council working paper examines past trends in the components of life expectancy at birth in high-income countries with low levels of mortality. The projection of these components provides the basis for assessing plausible future trends in longevity. Large increases in conventional life expectancy before 1950 are found to be primarily attributable to reductions in juvenile and background mortality. After 1950 the rate of improvement in life expectancy slowed, but senescent mortality fell more rapidly than before, thus becoming the main cause of rising life expectancy at birth. The analysis suggests that longevity improvements will be larger and population aging will be more rapid than many governments of high-income countries expect.
Bongaarts, John. 2006. "How long will we live?" Policy Research Division Working Paper no. 215. New York: Population Council. Version of record: https://doi.org/10.1111/j.1728-4457.2006.00144.x