创新型试点城市的建立能否降低环境污染?——基于准自然实验的证据

该文基于中国2004—2015年251个城市的面板数据,利用双重差分方法评估了创新型试点城市的建立对城市环境污染的影响,并运用双重差分倾向得分匹配法(PSM-DID)进一步进行了验证.研究结果表明:创新型试点城市的建立显著降低了城市环境污染,可以平均降低城市环境污染8.74%.机制检验表明:创新型试点城市的建立推动了城市绿色发展,主要通过技术效应和环境规制效应降低城市环境污染.城市规模异质性检验表明:II型大城市的创新型试点城市的建立加剧了环境污染,而其他规模类型的创新型试点城市的建立都具有减污效应.政策异质性检验表明:创新型试点城市建立受到“智慧城市”政策、“低碳城市”政策和“两控区”政策影响的地区的环境抑制效应更强,而受到“两控区”政策影响的创新型试点城市减污效应最大.区域异质性表明:西部地区减污效应比东部和中部更明显.

Can the Establishment of Innovative Pilot Cities Reduce Environmental Pollution?——Based on Evidence from Quasi-natural Experiments

Based on the panel data of 251 prefecture-level cities in China from 2004 to 2015,the double differential method is used to evaluate the impact of the establishment of innovative pilot cities on urban environmental pollution,and the double differential propensity score matching method(PSM-DID)is used to further verify.The study results show that the establishment of innovative pilot cities has significantly reduced urban environmental pollution,on average,it can reduce urban environmental pollution by 8.74%.The mechanism testing shows that the establishment of innovative pilot cities has promoted urban green development,mainly through technological effects and environmental regulatory effects reduce urban environmental pollution.The test of urban scale heterogeneity shows that innovative pilot cities of type II metropolitan scale aggravate environmental pollution, while other types of innovative pilot cities have pollution reduction effects.The test of policy heterogeneity shows that the establishment of innovative pilot cities is affected by the "smart city" policy,the "low-carbon city" policy and the "two-control area" policy,which has a stronger environmental restraint effect.The pollution reduction effect of innovative pilots cities that are affected by the "two-control area" policy is the largest.The regional heterogeneity shows that the pollution reduction effect in the western region is more obvious than in the eastern and central regions.