Heterogeneous Porter Effect or Crowded-Out Effect: Nonlinear Impact of Environmental Regulation on County-Level Green Total Factor Productivity of Pigs in the Yangtze River Basin of China

Green total factor productivity (GTFP) is critical to both the economic and ecological objectives of pig breeding. This research utilizes the SBM-ML model to calculate the GTFP of pig breeding in 381 counties within the Yangtze River Basin from 2014 to 2021. Then the GTFP is further decomposed into technical efficiency (MLEC) and technical progress (MLTC) to conduct in-depth exploration. The regression results reveal that: (1) Environmental regulation (ER) has significant double-threshold effects on GTFP, MLEC, and MLTC. (2) MLTC is the main force of GTFP growth, and stronger ER does not always lead to better GTFP growth. (3) GTFP is boosted by mechanization enhancement and industrial agglomeration limitation. (4) Counties in non-provincial capital cities and those closer to the river exhibit greater ER threshold effects. (5) Both pig price and transportation efficiency play a moderating role. (6) Further analysis demonstrates that ER simultaneously reduces pig production capacity and carbon emissions, as well as improves the water quality. And the reduction of ER, although beneficial for capacity, has a significant negative impact on GTFP. Finally, this study concludes with policy recommendations to boost the new quality productivity in the pig industry.