High-speed rail and urban innovation: based on the perspective of labor mobility

High-speed rail (HSR) can enhance the inter-regional flow of labor factors, which is conducive to promoting knowledge exchange and the formation of innovation. Using prefecture-level data and the China Migrants Dynamic Survey (CMDS), and adopting a difference-in-differences model, we explore the effect of HSR connection on urban innovation as well as its mechanisms. The results indicate that compared with non-HSR cities, the innovation in connected cities significantly improves after HSR connection. The results remain robust after using an instrumental variable to deal with the possible endogeneity problem caused by the nonrandom placement of the HSR routes. Further investigations on the mechanisms show that one reason for the innovation improvement in HSR cities is the flow of talents from non-HSR cities to connected ones. The other reason for this increase is that HSR reinforces the interaction of talents among cities along the HSR routes.