Planes, Trains and Automobiles: The Importance of Location for Knowledge Transfer in the Transportation Sector
Colorado College Working Paper No. 2012-10
13 Pages Posted: 10 Jun 2012
Date Written: June 10, 2012
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 physical distance is becoming less important for spillovers with time, albeit in a nonlinear fashion.
Keywords: Transportation Sector, Patents, Knowledge Clustering, Left-censored Tobit
JEL Classification: L62, R3, L2, Q55
Suggested Citation: Suggested Citation