How high-speed railway expands beyond local knowledge search in interdisciplinary innovation: Evidence from China

Breaking through local knowledge search limitations is essential for fostering interdisciplinary innovation. This paper investigates how High-speed Railway (HSR) facilitates these firms in integrating information technology (IT) knowledge from other cities into their innovation processes. By connecting cities through faster transportation, HSR diminishes the constraints of geographical proximity, enabling firms to bypass the traditional reliance on local knowledge clusters and access a broader pool of IT expertise. Utilizing a difference-in-differences (DID) approach, our results reveal that HSR enhances knowledge search scope by improving access to IT resources, increasing human capital mobility, and raising competitive awareness. Additionally, we identify heterogeneity in this effect based on factors such as the marketization level of a firm's location, the degree of digital infrastructure development, whether a firm is located in a provincial capital, and the specific industry sector. Our findings further demonstrate that the expansion of knowledge search scope due to HSR significantly boosts future firm performance. These findings highlight the critical role of transportation infrastructure, exemplified by HSR, in breaking down geographic barriers to interdisciplinary knowledge flows and fostering more dynamic innovation ecosystems.