Matching and Learning In Cities: Evidence From Patent Data
Using patents per capita (patent intensity) in a metropolitan area as a measure of innovation, the authors examine the role of knowledge spillovers on innovations in metropolitan areas. Findings indicate that patent intensity is positively related to the number of jobs per square mile (employment density) of metropolitan areas.
Link
http://www.phil.frb.org/files/wps/2004/wp04-16.pdf