The impact and spillover effect of urban agglomeration planning on the carrying capacity of land resources: Evidence from the Yangtze River Economic Belt

To enhance regional agglomeration and carrying capacity, the State Council and provincial governments have successively approved several urban agglomeration plans. However, the impact of urban agglomeration planning on land resource carrying capacity needs to be tested. Therefore, based on panel data from 117 cities both within and outside the planning scope of the five major urban agglomerations in the Yangtze River Economic Belt during the period of 2005-2022, this paper employs multi-period difference-in-differences model and mediation effect model to empirically explore the effect and mechanism of urban agglomeration planning on land resource carrying capacity, and analyzes spatial spillover effect through the spatial Durbin model. The main findings are as follows: (1) Urban agglomeration planning can effectively enhance the land resource carrying capacity, but it has different impacts on its subsystems. The results indicate that urban agglomeration planning significantly enhances the land economic carrying capacity, but it has a significant negative effect on the land ecological carrying capacity. (2) Urban agglomeration planning will enhance the land resource carrying capacity of cities within the urban agglomeration by enhancing urban innovativeness, government competitiveness, and public service supply capacity. (3) Urban agglomeration planning has a significant positive spillover effect on the land resource carrying capacity of neighboring cities, but this effect is spatially confined to the urban agglomerations, which are more mature in terms of development. These findings provide theoretical support and empirical evidence for improving urban agglomeration planning policies and enhancing land resource carrying capacity within the context of high-quality development.