This paper examines the evidence on the clustering of innovators within the telecommunications sector, using U.S. patent citation data to trace their locations over time. While clustering is clearly evident, we use multivariate left-censored Tobit regression analysis to control for identifiable...

Using over 200,000 U.S. patent citations, we test whether knowledge transfers in the transportation sector are sensitive to distance, and whether that sensitivity has changed over time. Controlling for self-citation by inventor, assignee and examiner, multivariate regression analysis shows that...

This paper examines the location of innovations within pharmaceutical technology, using U.S. patent citation data to trace the knowledge flows over time. It is clear that knowledge clustering is certainly present. Our study utilizes multivariate left-censored Tobit regression analysis to control...

This paper examines the location of innovations within green technology, using U.S. patent citation data to trace their inter-generational knowledge flows over time. Clustering is clearly evident, and we use multivariate left-censored Tobit regression analysis to control for identifiable...

Using over 250,000 U.S. patent citations, we test whether knowledge transfers in the energy sector are sensitive to distance, and whether that sensitivity has changed over time. Controlling for self-citation by inventor, assignee and examiner, multivariate regression analysis shows that physical...

We model the diffusion of economic knowledge using an epidemiological model of susceptible, exposed, infected, and recovered populations (SEIR). Treating bibliographic citations as evidence of contagion, we estimate the coefficients of a four-equation system simultaneously for each of 759...