Research on the Mechanism of the Impact of Population Aging in the Yangtze River Delta Urban Agglomeration on Economic Growth

In the context of the deep transformation of population structure and the coordinated advancement of high-quality development, exploring the mechanism of the impact of aging on economic growth has become a major issue related to the sustainable development of China. This study takes the 41 cities of the Yangtze River Delta urban agglomeration as a sample, using the population and economic census data from 2000 to 2020. It comprehensively applies an improved Solow model, GIS spatial analysis, spatial econometric models, and mediation effect tests to arrive at the following findings: (1) There is a significant asynchrony between economic growth and population aging in the Yangtze River Delta urban agglomeration. Economic growth has shifted from high-speed to high-quality development, while the aging process is accelerating and becoming more aged. (2) Population aging in the Yangtze River Delta has a nonlinear positive impact on economic growth. The intensity of this impact shows a characteristic of “strong-weak-strong,” with the first aging rate threshold being 11.63% and the second being 17.53%. (3) There is significant spatial autocorrelation between population aging and economic growth in the Yangtze River Delta urban agglomeration. The overall direction of the effect shows a spatial distribution pattern of “positive in the south and negative in the north.” The deepening of population aging in neighboring areas promotes local economic growth. (4) Labor productivity and optimization of the living environment constitute the core transmission pathways. Together, they account for more than 80% of the contribution and serve as the key mechanism for transforming aging pressures into growth momentum. This research provides practical guidance for solving the “rich” and “aging” contradictions in the Yangtze River Delta. It also offers a universal theoretical framework and a Chinese solution for aging economies worldwide to address the risk of growth stagnation.