The Global Demography of Ageing : Facts, Explanations, Future

The world is experiencing a sea change in its population age structure. People are living longer lives, and the share of older people in the total population is expanding rapidly. Between 2005 and 2050, the proportion of the population aged 60 and older will increase in every country in the world. This paper first reviews key facts and trends regarding past and projected population aging across regions. Next, we review the different hypotheses put forth in the economic and demographic literature on the causes of the phenomenon. Finally, we discuss the changing nature of aging, the future of longevity and associated policy implications