Can the opening of high-speed rail reduce environmental pollution? An empirical research based on difference-in-differences model

This study utilizes the opening of high-speed rail as a quasi-natural experiment and employs panel data from 281 Chinese cities at or above the prefectural level from 2003 to 2019 to empirically examine the impact of high-speed rail development on environmental pollution. The results indicate that the opening of high-speed rail significantly reduces environmental pollution, with varying degrees of effects on three types of industrial pollutants. The empirical findings pass the parallel trends test and dynamic effect test, revealing a lag of one year for the impact of high-speed rail on environmental pollution and an increasing effect on reducing industrial pollutant emissions over time. In this study, the core explanatory variable is replaced by the frequency of high-speed rail, and the baseline regression results demonstrate that an increase in high-speed rail frequency can decrease industrial pollutant emissions, with varying degrees of impact on different pollutants, ensuring the robustness of the results. Mechanism testing shows that the opening of high-speed rail can reduce environmental pollution through industrial structural adjustment and technological progress.