The demographic components of population aging in China.

Past trends in fertility and mortality in China have led to an age composition that will age rapidly in the coming decades. In this paper we examine measures of population aging in China from 1953 to 1982, and then project population aging to the year 2050 using a cohort-components methodology. The projected measures of population aging that result from these forecasts are then decomposed into the relative contributions that are made to these changes by past, present, and future trends in fertility and mortality. Results indicate that China's population will age at an unprecedented rate over the next 70 years, both in terms of the absolute size of the elderly population and their proportion of the total population. At least 50 percent of the projected increase in population aging in China between 1980 and 2050 will be a product of the momentum for aging that is already built into the present age structure and vital rates. However, prospective trends in the measures of population aging become increasingly more sensitive to varying assumptions about fertility and mortality with time, and as older age groups are considered. This analysis provides the demographic basis for evaluating the possible effects of population aging on health care, social security, and other social and economic issues.