The spatial spillover effect of China's pollutants emission trading pilot scheme on green efficiency: evidence from 285 China's cities

This paper firstly uses the DEA-based Range Directional Model (RDM) and the Global Malmquist-Luenberger (GML) index to calculate the Green Efficiency Index (GEI) of China's cities under the constraints of pollution emissions, energy consumption, and natural resource occupancy. The GEI shows that the average green efficiency of the 285 sample cities achieved a total improvement of 10.1% from 2003 to 2019. The average cumulative improvement rate of green efficiency in the 110 cities in Pollutants Emission Trading Pilot Scheme (PETPS) from 2003 to 2019 was 14.9%, which was higher than the average of non-pilot cities (8.6%). Subsequently, this paper constructs a spatial difference-in-differences model (Spatial-DID) to empirically test the green efficiency promotion effect of PETPS from two aspects: local and spatial spillover. It is found that PETPS can promote the progress of local green efficiency in pilot cities, but there is a spatial spillover effect that is not conducive to the green efficiency progress in surrounding areas. The results of the mediation effect analysis show that the launch of PETPS will significantly reduce the clustering of industrial production activities in the pilot cities, thereby accelerating the green efficiency progress. However, PETPS can also promote clustering of industrial production activities in surrounding areas, thereby inhibiting the green efficiency progress in surrounding areas. These analysis results can fully explain the cause of the negative spatial spillover effect of PETPS.