Stars and Comets: An Exploration of the Patent Universe
50 Pages Posted: 4 May 2011
Date Written: January 12, 2011
The analysis of patent and citation data has become a popular source of evidence on localized knowledge spillovers and innovation. Nevertheless, one aspect has been overlooked: the patent distribution across inventors is extremely skewed, as many inventors -- the comets -- register one or few patents, while a small number of inventors -- the stars -- register many patents. This raises a number of questions relating to the geography of innovation: do different categories of inventors interact with the local economic environment in the same way? Are they equally distributed over space or do they tend to concentrate? Is spatial proximity beneficial for their activity? Using a rich database on US inventors, we provide evidence suggesting that the two categories of patents are associated with different kinds of cities. We then test whether the activity of stars is beneficial for local comets, finding that a 10% increase in the number of patents authored by star inventors leads to a 3% increase in the number of patents developed by comet inventors.
Keywords: localized knowledge spillovers, patents, innovation
JEL Classification: R10, O31
Suggested Citation: Suggested Citation