Can population inflow mitigate the negative effect of aging on economic growth?

Demographic transition and population spatial distribution changes are two important issues in China at present. International experience indicates that aging has a negative effect on economic growth, and in the context of deepening aging, it is important to find measures to cope with the aging problem in order to achieve stable economic growth. An overlapping generation model incorporating population mobility factors is constructed to investigate whether population inflow can alleviate the negative effect of aging on economic growth. The theoretical analysis and numerical simulation results indicate that population inflow can mitigate the negative effects of aging mainly through three channels: increasing the household savings rate, promoting the accumulation of human capital, and reducing the household support ratio. Considering the scope of population spatial mobility and the differences in urban types, this study employs panel data from 258 prefecture-level cities in China over the period 2000–2020 to establish an econometric model, further examining the heterogeneity of the moderating role played by population inflow. The results indicate that from the perspective of the scope of population flow, both the inter-provincial and intra-provincial population inflows have a moderating effect, but the inter-provincial population inflow has a greater moderating effect. From the perspective of city type, the population flow in different types of cities has a moderating effect, but the population flow in high administrative-level cities and megacities has a greater moderating effect. The flow of population should be rationally guided to promote economic growth and address the negative effect of aging on economic growth.