The role of intra- and inter-regional relatedness and unrelatedness for the geography of breakthrough technological innovation: evidence from the US

Not all innovations are alike. Breakthrough technological innovations have a greater impact on regional development and are a key topic in economic geography. However, most studies focus on intra-regional factors, with little attention given to inter-regional perspectives. To address this, we extend the concepts of relatedness and unrelatedness density from the intra- to the inter-regional scale. Using US patent data from the period 1976–2015, we find that both intra-regional (un)relatedness density and inter-regional (un)relatedness density contribute to the emergence of breakthrough technological innovations in regions. Moreover, intra-regional relatedness density can reinforce the role of other types of (un)relatedness density in breakthrough technological innovations.