Intercity innovation collaboration and the role of high-speed rail connections: evidence from Chinese co-patent data
利用中国高铁建设作为准自然实验，基于2005-2018年城市对合作专利数据，发现高铁连接显著增加了城际合作专利数量、质量和合作伙伴数量，且对250公里内的城市对效果最强。
This study explores the extent to which changes in transport infrastructure counterbalance pre-existing geographical friction and foster innovation collaboration, using the Chinese high-speed rail (HSR) construction as a quasi-natural experiment. Using a comprehensive dataset of city-pair co-patents from 2005 to 2018, we show that HSR connections significantly increase intercity 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 settings, indicating a negative moderating effect of institutional distance. Various robustness methods are used to confirm the validity of our findings.