The Opening of High-Speed Railway and Coordinated Development of the Core–Periphery Urban Economy in China

The current study investigates the impact of the high-speed railway’s operation on the coordinated economic development of “core–periphery” cities using the multi-period difference-in-difference (DID) model. Data on 270 prefecture-level cities in China were collected for empirical analysis of collected data. The findings demonstrate that the high-speed railway’s operation has widened the economic development gap between core and peripheral cities and restrained the coordinated growth of the urban economy. The heterogeneity analysis found that the “siphon effect” of the high-speed railway’s operation in core cities is only effective within the distance of “one-hour metropolitan area”. Moreover, it is found that the high-speed railway has a threshold effect based on the size of cities. It depicts that the core cities in the high-speed railway network play a “siphon effect” and “diffusion effect” on large size cities and small (or medium) size cities, respectively, which is manifested as a suppression and promotion effect on the coordinated development of the urban economy. Furthermore, it is found that that technological innovation and economic agglomeration are two significant intermediary paths of high-speed railway opening that affect the level of “core–periphery” city economics coordination; however, technological innovation’s role as an intermediary has a stronger masking effect than economic agglomeration.