'With no siblings, but with a home': Single Patent-code Inventions (SPIs) and regional technological diversification

We investigate the extent to which the 'siloed' nature of regions' knowledge base affects their technological diversification. Drawing on recombinant innovation theory, we maintain that regions find it harder to specialise in technologies with a more siloed knowledge base, and that this hampering effect is more pronounced for more cognitively unrelated new technologies. Using data from the European Patent Office, with respect to sub-national regions of the EU28, we proxy the siloed degree of the regional knowledge base with the weight of Single Patent-code Inventions (SPIs) over total patents by region-technologies and test our hypotheses over the 1986-2017 period. We find that the relative number of SPIs by regional technologies - i.e. the siloed extent of these technologies - negatively correlates with the regions' capacity to specialise in them. This negative correlation attenuates with respect to the specialisation in more cognitively closer new technologies. For very high levels of technological relatedness, the correlation becomes positive and the SPI incidence tends to enable technological diversification, rather than contrasting it. Policy implications are drawn accordingly.