Long-run trends of human aging and longevity

Abstract

Over the last 200 years, humans experienced a huge increase of life expectancy. These advances were largely driven by extrinsic improvements of their environment (for example, the available diet, disease prevalence, vaccination, and the state of hygiene and sanitation). In this paper, we ask whether future improvements of life expectancy will be bounded from above by human life span. Life span, in contrast to life expectancy, is conceptualized as a biological measure of longevity driven by the intrinsic rate of bodily deterioration. In order to pursue our question, we first present a modern theory of aging developed by bio-gerontologists and show that immutable life span would put an upper limit on life expectancy. We then show for a sample of developed countries that human life span thus defined was indeed constant until the mid-twentieth century but increased since then in sync with life expectancy. In other words, we find evidence for manufactured life span.

Life Expectancy, Schooling, and Lifetime Labor Supply: Theory and Evidence Revisited

“…This result is very similar to the figure of T = 95 obtained by Gavrilov and Gavrilova (1991) from estimates of the compensation law using more than 200 historical life tables. 14 The findings by Strulik and Vollmer (2013) document that human life span has been approximately constant until about the 1950s, which is consistent with the compensation effect observed in US. Only in the last decades they find a moderate increase in longevity in terms of the life span in the more developed countries.…”

“…The process of progressive rectangularization of the survival function has been documented also by Wilmoth and Horiuchi (1999) for a sample of countries that have undergone the demographic transition and, more recently, by Strulik and Vollmer (2013), for the period 1900-2000 in a large cross-section of countries. 14 The same pattern has been documented for the preindustrial period 1000-1900 by de la Croix and Licandro (2012) using a cross-country data set on the mortality of famous individuals.…”

The Economic and Demographic Transition, Mortality, and Comparative Development

“…In spite of substantial changes in the health status at old age (which may facilitate old age labor supply) and the introduction of welfare programs (that anticipated retirement), the average age of retirement was relatively stable across historical cohorts in western countries. See Hazan (2009) and Strulik and Vollmer (2013). In an earlier version, the analysis abstracted from the possibility of retirement before death, with similar results.…”

Going from Bad to Worse: Adaptation to Poor Health, Health Spending, Longevity, and the Value of Life

“…Middle: Estimated association D(t) (Mitnitski et al, 2002a). Right: Predicted (line) and estimated (stars) association between age and survival probability (estimate from Strulik and Vollmer (2013). Implied life expectancy at 20: 55.3 years.…”