The impacts of high-speed rail networks on urban green innovation

In the current context of sustainable development in China, the inherent clean and rapid characteristics of high-speed rail (HSR) are reshaping both economic and green development patterns. From the perspective of HSR network centrality, this study employs a panel dataset encompassing 278 Chinese cities and constructs various difference-in-differences (DID) models to analyze the green innovation effects of the HSR network. Empirical findings indicate that the HSR network significantly stimulates urban green innovation, a conclusion further validated through robustness checks. The mechanism analysis reveals that the HSR network promotes the development of tourism economies along its route and the specialized agglomeration of producer service industries, which, in turn, enhances urban green innovation. Further analysis shows that the extent of this impact is influenced by various heterogeneous characteristics, such as urban size, tourism attributes, resource endowments, environmental institutional foundations, and the characteristics of different urban agglomerations. Additionally, the HSR network boosts green innovation levels in both local and neighboring regions, with the positive spatial spillover effect mainly occurring within 200 km. Our findings provide recommendations for promoting urban green innovation and optimizing the HSR network layout. Furthermore, this study enriches the literature on the environmental and economic effects of the HSR network.