The impact of industrial agglomeration on ecological efficiency: An empirical analysis based on 244 Chinese cities

Improving ecological efficiency is an integral part of the pursuit of high-quality economic development, and industrial agglomeration is a significant mechanism affecting ecological efficiency. This study measured the ecological efficiency of 244 Chinese cities from 2005 to 2017 using the super-epsilon-based measure model. Then, the impacts of industrial agglomeration on ecological efficiency and regional heterogeneity were empirically tested using dynamic spatial panel Durbin models based on the panel data of these cities. Finally, a mediating effect model was used to examine the role of the agglomeration effect between industrial agglomeration and ecological efficiency. There is a significant inverted U-shaped relationship between industrial agglomeration and ecological efficiency, and the level of ecological efficiency in most cities is smaller than the "agglomeration inflection point." In addition, the agglomeration effect is an important way for industrial agglomeration to influence ecological efficiency. With an increase in industrial agglomeration, the aggregation effect is transformed into a crowding effect, especially in the southeastern coastal area of China, where the crowding effect has already appeared. Therefore, this study argues that in order to improve ecological efficiency, it is necessary to formulate differentiated policies to minimize the crowding effect according to the regional development status.