Dynamics and driving mechanisms of the spatial mismatch between population aging and pension resources in the Yangtze River Delta

As one of the earliest and most severely aging regions in China, the Yangtze River Delta (YRD) exhibits a prominent spatial mismatch between population aging and pension resources. Using population and socio-economic data from 41 cities in the YRD for 2010 and 2020, this paper applies the spatial mismatch model to analyze the evolution of the spatial mismatch between population aging and pension resources, identifies city-level development patterns, and employs the optimal parameter-based geographical detector to reveal changes in the driving mechanisms underlying this mismatch. The results show that: (1) The population aging degree and the level of pension resources in the study area are on the rise, with the population aging increasing far faster than the pension resources. The population aging level is relatively high in Eastern Jiangsu province and Southern Anhui province. High-level pension resources are concentrated in developed cities such as Shanghai, Hangzhou and Nanjing, while third- and fourth-tier cities have lower levels. (2) The spatial mismatch in the region is evident, showing a pattern of "positive mismatch-positive and negative alternation-negative mismatch" from northwest to southeast. The number of cities with severe mismatch (experiencing a severe surplus or severe shortage of pension resources) and moderate mismatch (experiencing a moderate surplus or moderate shortage of pension resources) has decreased, while the number of cities with slight mismatch (experiencing a slight surplus or slight shortage of pension resources) has increased. (3) The degree of spatial mismatch is jointly shaped by multiple factors and their interactions. Among these, the impact of demographic factors is gradually declining, while the influences of policy, economic, and social factors are increasing significantly. The explanatory power of both the elderly dependency ratio and per capita general public budget expenditure is enhanced when they interact with other factors. The study provides scientific evidence and policy reference for promoting the spatial coordinated development of population aging and pension resources in the YRD.