Internal migration and regional differences of population aging: An empirical study of 287 cities in China.

In addition to birth and death, migration is also an important factor that determines the level of population aging in different regions, especially under the current context of low fertility and low mortality in China. Drawing upon data from the fifth and sixth national population census of 287 prefecture-level cities in China, this study explored the spatial patterns of population aging and its trends from 2000 to 2010 in China. We further examined how the large-scale internal migration was related to the spatial differences and the changes of aging by using multivariate quantitative models. Findings showed that the percentage of elder cities (i.e. proportion of individuals aged 65 and above to total population is higher than 7%) increased from 50% to 90% in the total 287 cities within the decade. We also found that regional imbalances of population aging have changed since 2000 in China. The gap of aging level between East zone and the other three zones (i.e. West, Central, and North-east) has considerably narrowed down. In 2000, Eastern region had the greatest number (65) of and the largest proportion (74.7%) of elder cities among all four regions. By 2010, the proportion (87.4%) of elder cities in the eastern region was slightly lower than Central (91.4%), Western (88.2%) and North-east sectors (91.2%). Results from multivariate quantitative models showed that the regional differences of population aging appear to be affected much more by the large-scale internal migration with clear age selectivity and orientation preference than by the impact of fertility and mortality. Population aging is expected to continue in China, which will in turn exacerbate regional imbalances. Policies and implications are discussed to face the challenges that the divergent aging population may present in China.