Proximity, network centrality, and university–industry collaboration: Evidence from the Yangtze River Delta, China

Existing proximity research has increasingly recognized the dynamic relationship between proximities and innovation networks, yet less is known about how network centrality conditions proximity effects in intercity university–industry (UI) collaboration. This paper develops a multidimensional proximity framework that incorporates cities’ network positions and actor heterogeneity to examine the formation of intercity UI collaboration. Using PPML-HDFE and UI co-patent data for Chinese cities from 2006 to 2020, we focus on the Yangtze River Delta (YRD) and compare collaboration within the region with linkages between the YRD and the rest of China. The results show that cognitive proximity is the strongest non-spatial driver of intercity UI collaboration, highlighting the importance of absorptive capacity and technological relatedness. However, excessive cognitive similarity may generate redundancy and lock-in. This proximity paradox is not consistently moderated by aggregate network centrality; rather, decomposing centrality by actor type reveals that university-based centrality provides a more stable buffering effect than industry-based centrality. Universities, therefore, act as key gatekeepers that help cities access, translate and recombine external knowledge. The findings also show that geographical distance remains more robust than temporal proximity, suggesting that HSR connectivity is non-random. Organizational proximity, such as university branches and off-site research institutes, promotes collaboration but remains constrained by spatial frictions. Overall, the study demonstrates that proximity mechanisms are not fixed, but vary across actor types and spatial scales, and are conditioned by the structural positions cities occupy in collaboration networks. Policy interventions should therefore strengthen university-centred cross-regional linkages while avoiding excessive concentration of innovation resources in core cities.