高铁开通能提升城市绿色全要素生产率吗?

Can the opening of high-speed rail improve urban green total factor productivity?

将高铁开通视为一项准自然实验,基于2006—2016年中国281个地级市的面板数据,创新性地将社会网络分析与连续双重差分法相结合,实证验证高铁开通以及高铁网络对城市绿色全要素生产率的影响,并进一步分析其影响路径及空间溢出效应。研究发现:高铁开通能够显著提升城市绿色全要素生产率,但是驱动效应在城市规模、区位、地理圈层和等级方面存在显著的异质性;高铁开通对城市绿色全要素生产率的影响存在明显的滞后性,这一效应在高铁开通后第2年开始显现,而在第4年开始减弱;随着城市在高铁网络中的重要性不断提升,高铁开通对城市绿色全要素生产率的提升效应将不断增强;高铁开通间接带来的技术创新效应和结构优化效应是驱动城市绿色全要素生产率提升的主要力量,且均存在时滞,而直接替代效应尚未显现;另外,高铁开通对邻近城市绿色全要素生产率存在显著的正向空间溢出效应。研究结论进一步完善了高铁的经济环境效应评估,为理解高铁与城市发展质量之间的关系提供了新的经验证据,对优化高铁布局也有重要启示意义。

This article regards the opening of high-speed rail as a quasi-natural experiment. Based on the panel data of 281 prefecture-level cities in China from 2006 to 2016, this paper innovatively combines social network analysis with the continuous difference-in-differences method to empirically verify the impact of opening high-speed rail and high-speed rail networks on urban green total factor productivity, and further analyzes the impact path and spatial spillover effects. The results are as follows. The opening of high-speed rail can significantly improve the urban green total factor productivity, but the effect is significantly heterogeneous in terms of city size, location, geographic circle and level. Obviously, the impact of high-speed rail opening on urban green total factor productivity lags somewhat: it is significant in the second year after opening, and begins to weaken in the fourth year. As the importance of cities connected to the high-speed rail network continues to increase, the effect of high-speed rail opening on urban green total factor productivity will continue to increase. The technical innovation effect and structural optimization effect indirectly brought about by the opening of high-speed rail are the main forces driving the increase of urban green total factor productivity, while there is a time lag, and the direct substitution effect has not yet appeared. In addition, the opening of high-speed rail has had a significantly positive spatial spillover effect on the green total factor productivity of neighboring cities. Our research enables us to further evaluate the economic and environmental effects of high-speed rail, provides new evidence for understanding the relationship between high-speed rail and the quality of urban development, and also highlights important implications for optimizing the layout of high-speed rail.