Transport infrastructure and health equity among older adults: evidence from a quasi-natural experiment on high-speed rail in China

Abstract

Against the backdrop of rapid population aging, large-scale intercity transportation infrastructure not only improves regional accessibility but also reshapes patterns of resource distribution and social interaction, thereby influencing the health and health equity of older adults. Taking the opening of China’s high-speed rail (HSR) network as a quasi-natural experiment, this study uses panel data from the China Health and Retirement Longitudinal Study (CHARLS) spanning 2011–2020 and applies a difference-in-differences (DID) approach to evaluate the health effects of this type of transportation infrastructure. The results show that HSR openings significantly improve the health of older adults (β = 0.091, p < 0.01). Channel analysis indicates that HSR development is significantly associated with improvements in economic conditions, social participation, and environmental quality, suggesting that these factors may serve as important pathways through which HSR influences health. Heterogeneity analysis further reveals that the health benefits are more pronounced among older adults with lower educational attainment and lower income, indicating that the health gains from HSR development are concentrated among socioeconomically disadvantaged groups. Additional analysis based on the Kakwani relative deprivation index shows that HSR development contributes to reducing health disparities among older adults (β = − 0.016, p < 0.01). Overall, the findings highlight the role of HSR as a large-scale intercity transportation infrastructure that reshapes accessibility and resource distribution, thereby contributing to improvements in health and health equity among older adults. The study provides empirical evidence for transportation planning and public health policymaking in aging societies.