Intercity Innovation Collaboration and the Role of High-speed Rail Connections: Evidence from Chinese Co-patent Data

This study explores the extent to which changes in transport infrastructure counterbalance pre-existing geographic friction and foster innovation collaboration, using the Chinese HSR construction as a quasi-natural experiment. Using a comprehensive dataset of city-pair co-patents from 2005 to 2018, we show that HSR connection significantly increases inter-city co-patents, patent quality, and collaborative partnerships, and such effects are strongest for city-pairs within 250 km and decrease for longer distances. Moreover, the HSR effect is stronger for cities in similar institutional setting, indicating a negative moderating effect of institutional distance. Various robustness methods are used to confirm the validity of our findings.