Urban-rural gap induced by high-speed rail: 35 years of evidence from Japan

Over the past 35 years, the development of high-speed rail (HSR) in Japan has markedly enhanced market access and altered spatial distributional dynamics, thereby transforming the socioeconomic landscape in both urban and rural areas. This study delves into the impact of improved market access on regional disparities, with a particular focus on the shifts in population and economic activity between urban centers and their surrounding peripheral regions. We examine three key hypotheses: (1) HSR influences population dynamics, potentially leading to population decline in underdeveloped areas; (2) it affects demographic patterns, particularly in rural areas; and (3) it contributes to economic disparities, enhancing urban prosperity potentially at the expense of rural regions. Our analysis reveals pronounced effects of HSR: urban areas, exemplified by Tokyo, have seen substantial socioeconomic gains including a 26.10% income rise and an 18.34% population increase. Conversely, rural regions exhibit declining economic indicators with income dropping by 6.32% and population falling by 6.83%, accompanied by aging demographics. These trends, further illuminated by night-time light (NTL) data, underscore the uneven impact of HSR. Simulations suggest the continuation of these patterns with future HSR expansions. The study highlights the need for strategic policy measures to address the growing spatial disparities induced by HSR, advocating equitable infrastructure development and sustainable urban planning.