The role of external linkages and gatekeepers for the renewal and expansion of U.S. cities’ knowledge base, 1990-2004

This paper examines the role of external linkages and gatekeepers for the renewal and expansion of cities’ knowledge base, by presenting new evidence about co-invention networks in U.S. metropolitan areas based on European Patent Office (EPO) data for the period 1990-2004. We argue that the relative importance of direct external linkages and external relations mediated by gatekeepers varies according to specific local conditions. In particular, our findings suggest that external relations are on average a chief conduit to inject non-redundant knowledge at the local level and contribute to broadening and rejuvenating the local knowledge base. However, cities are quite heterogeneous in how they benefit from external relations. Whereas direct external connections outperform, on average, external links mediated by gatekeepers, the latter are especially important in cities with a localized and specialized knowledge base, as they enable the trans-coding and absorption at the local level of externally sourced knowledge.