This article aims to study the impact of China’s Two Control Zones policy on sulfur dioxide emissions from 1997 to 2018. First, this paper applies the DID model and uses the panel data of prefecture-level cities to preliminarily analyze the impact of the Two Control Areas Policy on sulfur dioxide. DID results show that the two control zones policy has indeed played a role in reducing sulfur dioxide emissions. After individually controlling the covariates, the two control zones policy has a minor effect on promoting the reduction of sulfur dioxide emissions. The covariates are sorted in order of reduction degree from small to large, namely Popu, GDP, industry, and FDI. By continuously adding control variables, it can be found that the addition of GDP has almost no effect on the emission reduction effect of the two control areas policy. FDI and Popu has a worsening effect on the emission reduction effect of the two control areas policy; the addition of industry can reduce sulfur dioxide The deteriorating effect of the platoon will be partially offset. Secondly, to reduce the error of DID estimation, this paper further uses the PSM-DID method for the robustness test. The PSM-DID inspection results once again confirmed that the two control areas policy has a significant role in reducing acid rain and sulfur dioxide pollution in the region. Finally, based on the analysis results of the two models, this article proposes corresponding policy recommendations on further using the two control areas policy to reduce sulfur dioxide emissions from the perspective of the government and enterprises.
Keywords Two Control Zones, sulfur dioxide emissions, Double difference