Tracks of equality: high-speed rail and its effects on intra-regional inequality—a quasi-experimental study based on China’s district/county-level data

The efficacy of high-speed rail (HSR) remains controversial, with critics contending that its welfare disproportionately accrues to affluent demographics, potentially exacerbating inequality. In this study, we employ nighttime light data at the district/county level in China from 2000 to 2019 to construct a nighttime light inequality index as a proxy for intra-regional inequality. Utilizing a quasi-experimental approach (Difference-in-Differences), we investigate the impact of HSR implementation on intra-regional inequality in China. We find that HSR significantly reduces inequality along its routes, with districts/counties experiencing mitigation of local disparities primarily through three channels: technological innovation, entrepreneurial activity, and urban expansion. HSR’s inequality-reducing effects are most pronounced in megalopolis with multiple centers and balanced structural layouts. The presence of national-level tourist attractions enhances HSR’s mitigating effect on local inequality. Notably, red tourism sites associated with Chinese Communist Party history exhibit a more substantial augmenting impact on HSR’s inequality-reducing effects compared to conventional tourist attractions. Our research findings contribute to the ongoing discourse regarding the welfare effects of HSR and offer policy implications for developing nations contemplating HSR as a means to alleviate poverty and stimulate economic growth.