城市低碳治理对生态效率的影响--基于低碳城市试点政策的准自然实验

The Impact of Urban Low-carbon Governance on Ecological Efficiency:A Quasi-natural Experiment Based on the Low-carbon City Pilot Policy

低碳城市建设和生态效率提升是城市实现高质量发展的重要途径。基于“波特假说”和“遵循成本假说”理论,文章利用2007—2018年中国283个城市的面板数据,运用DID方法实证考察了低碳城市试点政策对生态效率的影响。研究发现:低碳城市试点政策能够显著提升城市生态效率水平,这一结论在分别进行PSM-DID检验、平行趋势检验、安慰剂检验等多种情景下依然稳健;异质性检验表明,低碳城市试点政策对东部地区以及非资源型城市的正向作用较强;从影响机制看,低碳城市试点政策通过推动产业结构升级和技术创新,从而促进生态效率提升;进一步地,低碳城市试点的政策效应存在正向空间溢出效应,即其对相邻城市的生态效率提升具有显著正向影响。

Low carbon city construction and ecological efficiency improvement are important ways for cities to achieve high-quality development.Based on the theories of"Porter hypothesis"and"cost compliance hypothesis",this paper uses the panel data of 283 cities in China from 2007 to 2018 to empirically examine the impact of low-carbon city pilot poli‐cies on ecological efficiency using DID method.It is found that low-carbon city pilot policies can significantly improve the level of urban ecological efficiency,and this conclusion is still robust under multiple scenarios such as PSM-DID test,parallel trend test,and placebo test;heterogeneity test indicates that the pilot policy for low-carbon cities has a strong positive effect on the eastern region and non resource-based cities;from the perspective of impact mechanism,low-carbon city pilot policies promote ecological efficiency by promoting industrial structure upgrading and technological inno‐vation.Further,the policy effect of low-carbon city pilot has a positive spatial spillover effect,that is,it has a significant positive impact on the improvement of ecological efficiency of adjacent cities.