长江经济带高铁开通对城市生态效率的影响——基于DID与SDID的实证分析

Impact of High-speed Rail on Urban Ecological Efficiency in the Yangtze River Economic Belt:Empirical Analysis Based on DID and SDID

文章对高铁开通影响生态效率的理论机制进行分析,认为高铁开通将形成一种跨越区域界限的影响,这一影响可分为本地效应和溢出效应。进一步基于2007—2018年长江经济带108个城市的面板数据,借助SBM-Undesirable模型测算出城市生态效率,利用高铁开通作为一项准自然实验,运用双重差分模型、PSM-DID模型、空间双重差分模型以及一系列稳健性检验的方法评估了高铁开通对城市生态效率的本地效应和溢出效应。研究发现:高铁开通显著提高了节点城市的生态效率;中介机制分析表明,高铁建设主要通过产业结构升级效应和技术创新效应促进了节点城市生态效率的提升;空间双重差分结果表明,高铁开通不仅改善了节点城市的生态效率,而且显著促进了周边城市生态效率的提升。

This paper analyzes the theoretical mechanism of the impact of high-speed rail on ecological efficiency,and holds that the opening of high-speed rail will form an impact across regional boundaries,which can be divided into local effect and spillover effect.Further,based on the panel data of 108 cities in the Yangtze River Economic Belt from 2007 to2018,the SBM Undesirable model is used to measure the urban ecological efficiency.Taking the opening of high-speed railway as a quasi-natural experiment,the DID model,PSM-DID model,SDID model,and a series of robustness tests are used to evaluate the local effect and spillover effect of the opening of high-speed railway on urban ecological efficiency.It is found that the opening of high-speed rail significantly improves the ecological efficiency of node cities;the analysis of intermediary mechanism shows that the high-speed rail construction promotes the ecological efficiency of node cities mainly through the effect of industrial structure upgrading and technological innovation;the spatial double difference results show that the opening of high-speed railway not only improves the ecological efficiency of node cities,but also significantly promotes the ecological efficiency of surrounding cities.