The influence and acting pattern of China's national carbon emission trading scheme on regional ecologicalization efficiency of industry.

To achieve the goal of energy conservation and emission reduction, China has launched its national carbon-emission trading scheme (ETS). Therefore, it is of great significance to evaluate the implementation of ETS from the perspective of regional ecologicalization efficiency of industry. Based on the panel data of 30 provinces and cities from 2007 to 2019, this study takes the SBM-DEA model to measure the regional ecologicalization efficiency of industry, uses the Difference-in-Difference (DID) model to evaluate the influence of ETS on the regional ecologicalization efficiency of industry, and verifies the outcome by propensity score matching method and counterfactual test. The mediating effect model is used to test the acting pattern of ETS on the regional ecologicalization efficiency of industry. The results show that: (1) ETS can significantly improve the ecologicalization efficiency of industry and shows regional heterogeneity. (2) ETS promotes regional energy conservation, emission reduction, and economic development because of the upgrading of structural optimization, agglomeration of resource synergy, and optimization of ecology. This study offers penetrating insights into the positive operation of the carbon market and provides some useful hints for the development of China's regional economy.