As a backdrop for subsequent chapters, this chapter describes the current demographic situation of the world's elderly and considers how the future situation might evolve. In addition to reviewing numbers and proportions of elderly people around the world, the discussion provides an overview of the dynamics of population aging, the increasingly important influence of changes in mortality at older ages on overall population aging, and the uncertainty such changes may introduce into our best efforts to project the size and composition of tomorrow's older population.
Estimates for the year 2000 indicate an aggregate global total of 419 million persons aged 65 and over, 6.9 percent of the earth's total population. As noted in Chapter 1, the net balance of the world's elderly population is currently increasing by more than 750,000 people each month; two decades from now, the increase will likely be 2 million per month. The number of persons aged 65 and over has increased by 289 million since 1950 and by 99 million just since 1990. 2 In 1995, 30 countries had elderly populations of at least 2 million; projections to the year 2030 indicate that more than 60 countries will reach this level. 3
Population aging refers most commonly to an increase in the percentage of all extant persons who have lived to or beyond a certain age. While the size of the world's elderly population has been increasing for centuries, it is only in recent decades that the proportion has caught the attention of researchers and policy makers. Italy was the demographically oldest of the world's major 4 nations in 2000, with more than 18 percent of
2The demographic estimates and projections in this chapter are taken from two sources. Unless otherwise noted, estimates prior to 1990 are from the latest revision of World Population Prospects (United Nations, 1999). Estimates and projections from 1990 onward are from the International Data Base maintained by the International Programs Center, U.S. Bureau of the Census, and supported by the Office of the Demography of Aging, U.S. National Institute on Aging.
3Though these and other projected figures are by no means certain, they may be more accurate than demographic projections of total population because the latter must incorporate assumptions about the future course of human fertility. Short- and medium-term projections of tomorrow's elderly are not contingent upon fertility because anyone who will be aged 65 or over in 2030 has already been born. When projecting the size and composition of the world's future elderly population, human mortality is the key demographic component. As discussed later in this chapter, current and future uncertainties about changing mortality, particularly at the oldest old ages, may produce widely divergent projections of the size of tomorrow's elderly population.
4Some small nations or areas of special sovereignty, such as Monaco, San Marino, and the Isle of Man, have high percentages of elderly among their populations. Monaco's percentage is higher than that of Italy.