Do high-speed railways have an impact on population change? evidence from Japan

The Shinkansen high-speed railway (HSR) network in Japan has greatly improved the efficiency with which people can travel and relocate between different regions of Japan. The ease with which people can now reach different cities and regions has helped to increase the balance and diversity of Japan’s population distribution. This study empirically examined the relationship between HSRs and population change in the context of Japan’s ongoing population decline. Using panel data for the years 1995, 2000, 2005, 2010, and 2015, an empirical analysis was conducted using the econometric propensity score matching-difference-in-difference (PSM-DID) method and by creatively applying 1-km grid data. This information was used to quantify the causal effect of the Shinkansen’s opening and to determine whether it resulted in an increase or decrease in the population size of the areas around the Shinkansen stations, all while taking into account the heterogeneity of individual Shinkansen stations. Finally, we reached the following conclusions: (1) The opening of the Shinkansen stations has had a significant impact on population change, and has produced a siphoning effect; (2) the analysis of dynamic effects revealed that different stations have different levels of impact in terms of population change and growth effects; and (3) the Shinkansen stations do not strictly adhere to administrative boundaries in terms of the scope of their impact on population change; rather, they have an effect on a wider geographic space. Finally, we analyzed the benefits and problems associated with the population siphoning effect produced by the Shinkansen in terms of population concentration and population loss in different areas, respectively. It is hoped that this analysis can provide a reference point for planners interested in understanding the broader impacts of large-scale HSR developments, as well as for policymakers who are considering HSR development as a policy tool.