创新的翅膀：直航连通促进中国城际合作专利

摘要

Modern transportation has weakened the constraints of geographical distance on the flow of knowledge. This study investigates the impact of direct air connectivity on intercity collaborative innovation in China using theoretical models and a staggered DID approach. Utilizing data on newly established direct flights from 2003 to 2021, we find that such routes raise co-invented patents by about 20.4%, a larger effect than that reported for high-speed rail in existing literature. Based on the agglomeration economy micro-foundations, we identify three primary mechanisms: it (i) reduces frictions in inter-firm market integration, enhancing the sharing of suppliers, customers, and complementary resources; (ii) reinforces preferential matching with existing partners, improving collaboration efficiency; and (iii) expands the scope and direction of intercity knowledge flows, strengthening mutual learning and absorptive capacity. Further analysis reveals a potential crowding-out effect between high-speed rail and air travel within the 200–800 km range, suggesting modal competition in this intermediate distance band. Also, direct air routes promote the diffusion of innovation resources from stronger to weaker cities, forming a “strong‑leading-weak” pattern of collaborative innovation. Our findings suggest that enhancing air transport infrastructure helps reduce spatial disparities in innovation resources and reinforces the resilience of cross-regional innovation networks.