区域协同治理政策的大气污染减排效应研究——基于双重差分法的实证检验

区域协同治理政策是中国提升大气污染治理效果的关键。首先对政策执行可能产生的治理效果展开分析，提出假设1~4；进一步以地级及以上城市的工业SO2为典型污染物，构建双重差分模型（DID）评估区域协同治理政策的减排效果，以及技术创新、产业结构和对外开放三种中介路径下的间接影响。结果显示：(1).以京津冀和长三角地区城市为实验组，其它城市作为对照组，区域协同治理政策的影响系数为-1.3427，政策显著降低污染排放水平，结果具有良好的稳健性。(2).分样本检验显示，京津冀地区政策效果明显优于长三角地区，经济发达地区的政策效果高于欠发达地区，政策执行中的区域异质性不容忽视。(3). 三条中介路径中，区域协同治理政策通过技术创新和对外开放的污染减排效果显著，而通过影响产业结构产生的间接驱动效果微弱。继续推动区域协同治理政策落实中，充分考虑区域差异化特征基础上，重视中介路径的识别和可能带来的减排潜力应成为重要的政策优化方向。

Regional Cooperative Governance Policy Effect Research on Air Pollution Reduction: Based on DID Model

Regional cooperative control policy is the key to improve the effectiveness of air pollution control in China. Firstly, the possible governance effects of policy implementation are analyzed, and hypotheses 1~4 are put forward. Furthermore, the industrial SO2 of prefecture-level cities and above was taken as the typical pollutant, and the difference-in-differences model (DID) was constructed to evaluate the emission reduction effect of regional collaborative governance policies, as well as the indirect impact of technological innovation, industrial structure and opening to the outside world. The results show that :(1). taking cities in the Beijing-Tianjin-Hebei region and the Yangtze river delta region as the experimental group, and other cities as the control group, the influence coefficient of regional collaborative governance policy is -1.3427, the policy significantly reduces the pollution emission level, and the model results are robust. (2). The sub-sample test shows that the policy effect of the Beijing-Tianjin-Hebei region is significantly better than that of the Yangtze River Delta region, and the policy effect of the economically developed region is higher than that of the less developed region. The regional heterogeneity in policy implementation cannot be ignored. (3) Among the three intermediary paths, regional collaborative governance policies have significant effect on pollution reduction through technological innovation and opening up, while the indirect driving effect through influencing industrial structure is weak. To further promote the implementation of regional collaborative governance policies, on the basis of full consideration of regional differentiation characteristics, attention should be paid to the identification of intermediary paths and the potential for emission reduction.