Co-inventor Networks and Knowledge Production in Specialized and Diversified Cities

Why do some cities produce more knowledge than others? The standard explanation rests upon the social networks that connect economic actors, within and between cities, and that structure the quantity and the quality of interactions from which new ideas are generated. These interactions are increasingly understood as shaped by different forms of proximity that congeal, at different times in different places, in complex assemblies that give rise to different forms of competitive advantage. Recent research focusing on the U.S. urban system has shown that metropolitan regions characterized by more extensive local and non-local network ties outperform cities where economic agents are isolated. However, across most of this work, little attention is given to the character of the local knowledge base and whether that is related to the structure of co-inventor networks. In this paper, we show that the social networks linking co-inventors differ between cities that produce specialized knowledge and those that produce diversified knowledge. These ideas are extended in models of tie-formation that show inventors in specialized cities value spatial proximity less and cognitive proximity more than inventors in diversified cities as they partner with collaborators from other urban areas.