Inter‐City Collaborative Innovation and Synchronization of Regional Economic Growth: Evidence From China

ABSTRACT This paper investigates whether inter‐city collaborative innovation promotes synchronization of regional economic growth in China. Using panel data on 295 cities from 2000 to 2023, we measure collaboration through joint patent applications and synchronization of nighttime light. To address endogeneity, we exploit historical human capital flows from the 1952 nationwide university restructuring as an instrumental variable. The results show that stronger collaborative innovation significantly fosters regional convergence. The effects are more pronounced across provinces and between geographically distant or culturally dissimilar cities, but weaker within provinces. Mechanism analyses indicate that collaborative innovation works through enhancing factor mobility and reshaping industrial specialization. These findings suggest that while collaborative innovation can reduce regional disparities, its impact is conditioned by geography, culture, and institutional boundaries. The study highlights the importance of cross‐regional governance and targeted policies to ensure that innovation cooperation translates into more balanced development.