An institutional experiment: how China’s government-led innovation corridor reshapes collaborative innovation behaviour within urban agglomerations

China is conducting a large-scale institutional experiment by positioning innovation corridors as a key policy instrument for high-quality development within urban agglomerations. Using China’s pioneering G60 Innovation Corridor as a case study, this paper examines the impact of corridor development on inter-city collaborative innovation within the urban agglomeration, drawing on joint invention patent data in strategic emerging industries. The G60 Innovation Corridor significantly enhances collaborative innovation among cities along its route, increasing both the extensive and intensive margins of inter-city collaboration and strengthening collaboration among different types of innovation actors. Heterogeneity analysis shows that the corridor strengthens cooperation among developed cities and promotes cross-tier linkages between developed and relatively underdeveloped cities, thereby exhibiting a ‘hub-and-spoke’ pattern. Further analysis shows that the corridor’s effects on innovation linkages beyond the corridor vary across the urban hierarchy, with stronger effects for city pairs involving developed cities and a significantly weaker effect for linkages between relatively underdeveloped cities inside and outside the corridor. In addition, high-speed rail connectivity strengthens the spillover effects of the corridor on collaborative innovation.