High-Speed Rail Opening and Inclusive Green Growth: Empirical Evidence from the Yangtze River Economic Belt

The Yangtze River Economic Belt serves as a pilot region for China’s strategy of ecological priority and green development. Through its time–space compression effect, the launch of high-speed rail can significantly shape factor flows and industrial distribution. Therefore, investigating the relationship between high-speed rail opening and inclusive green development carries important practical significance. This study selects 110 cities in the Yangtze River Economic Belt as research samples and constructs an inclusive green development evaluation system covering three dimensions: economic growth, social equity, and ecological sustainability. On this basis, a multi-period difference-in-differences model is employed to identify the effect of high-speed rail opening on inclusive green development, and the mediation and moderation effect models are used to reveal its mechanism. Given the staggered rollout of high-speed rail across cities, heterogeneity-robust estimators and a series of sensitivity analyses are further employed to examine the robustness of the baseline results. The empirical results show the following: (1) Under the preferred two-way fixed-effects specification, the average effect of high-speed rail opening on inclusive green development is statistically insignificant. The dynamic and heterogeneity-robust estimates indicate a delayed effect that becomes significantly positive six to seven years after opening, suggesting an economically meaningful accumulated effect in the longer run. (2) Technological innovation and industrial structure upgrading are examined as transmission channels. The point estimates are consistent with the proposed directions, but the mediation evidence is statistically weak and is reported as suggestive rather than conclusive. (3) Environmental regulation significantly strengthens the relationship between high-speed rail and inclusive green development, whereas the moderating role of financial development is not statistically significant. (4) The estimated effects show no significant regional differentiation under the preferred specification, and a negative association appears among provincial capital cities. This study provides theoretical support and practical reference for optimizing the layout of the high-speed rail network in the Yangtze River Economic Belt and promoting the coordinated development of transportation infrastructure construction and inclusive green development.