Has Environmental Regulation Promoted the Spatial Agglomeration of Hog Production in Administrative Border Regions? Evidence from the Yangtze River Basin in China

This study finds that the livestock environmental regulation (LER) imposed by China has promoted the spatial agglomeration of hog production in the administrative border areas, thereby posing a threat to ecological sustainability. We apply the difference-in-differences-in-differences (DDD) method to a unique dataset in counties along the main stem and 38 important tributaries of the Yangtze River basin in China from 2008 to 2019. Specifically, the slaughter volume and density of hogs in the most downstream border counties of a city are 7.87% and 9.56% higher, respectively, than those of otherwise identical counties within the same municipal jurisdiction. Conversely, in the most upstream border counties, these figures decreased by 12.02% and 15.35%, respectively. Moreover, we find that the fixed capital investment in the most downstream border counties is 22.54% less than that in otherwise identical counties. These findings imply that LER has driven the agglomeration of hog production in downstream administrative border areas, inadvertently shifting the pollution burden to these regions and posing potential challenges to the effectiveness of environmental policies.