高铁开通对城市绿色创新的影响研究——基于多期双重差分法的实证检验

Study on the Impact of High-speed Rail Opening on Urban Green Innovation-An Empirical Test Based on Multi-Period DID Model

高铁作为中国新型交通基础设施,其高效便捷的运输方式对于提升城市经济关联、促进绿色创新具有重要影响。本文基于2004~2019年中国城市面板数据,借助SBM-DEA模型对城市绿色创新指数进行了测度,并利用多期DID模型实证检验了高铁开通对城市绿色创新的影响及作用机制。研究结果显示,高铁开通能促进城市绿色创新,经过一系列稳健性检验后,该研究结论依然成立。从作用机制看,高铁开通作用于生产性服务业集聚进而促进城市绿色创新。异质性分析方面,高铁开通促进了长三角城市群和粤港澳大湾区以及中心城市的绿色创新,而对京津冀城市群和非中心城市的影响较弱。

As a new type of transportation infrastructure in China,high-speed rail has an important impact on improving ur⁃ban economic connection and promoting green innovation with its efficient and convenient mode of transportation.Based on the panel data of prefecture-level cities in China from 2004 to 2019,this paper measures the green innovation level of each prefecture-level city with the help of SBM-DEA model,and uses the multi-period DID model to test the impact and mechanism of high-speed rail opening on urban green innovation.The results show that the opening of high-speed rail can promote green innovation in cities,af⁃ter a series of robustness tests,this conclusion still holds.The impact of high-speed rail on urban green innovation is mediated by the agglomeration of producer services.In addition,the opening effect of high-speed rail has obvious heterogeneity.The opening of high-speed rail has promoted the green innovation of Yangtze River Delta urban agglomerations and the Greater Bay Area,while the impact on the Beijing-Tianjin-Hebei urban agglomeration is not obvious.The opening of high-speed rail promotes green innovation in central cities,but has no significant effect on green innovation in non-central cities.