Article: A New Perspective on Population Aging

A new perspective on population agingWarren C. Sanderson, Sergei Scherbov, Demographic Research Vol.16, No. 2 (January 2007) [ Abstract |]

Abstract:  In Sanderson and Scherbov (2005) we introduced a new forward-lookingdefinition of age and argued that its use, along with the traditionalbackward-looking concept of age, provides a more informative basis uponwhich to discuss population aging. Age is a measure of how many years aperson has already lived. In contrast, our new approach to measuringage is concerned about the future. In this paper, we first explore ournew age measure in detail and show, using an analytic formulation,historical data, and forecasts, that it is, in most cases, insensitiveto whether it is measured using period or cohort life tables. We, then,show, using new forward-looking definitions of median age and the oldage dependency ratio, how combining the traditional age concept and ournew one enhances our understanding of population aging.