We examine the relationship between firm size and research productivity in the pharmaceutical industry. Using detailed internal firm data, we find that larger research efforts are more productive, not only because they enjoy economies of scale, but also because they realize economies of scope by...

It is well known that patent citations occur disproportionately between patents issued to inventors living in the same location, which has been taken as evidence of geographically localized knowledge spillovers. In this study, we find that patent citations also occur disproportionately often in...

We examine how the spatial and social proximity of inventors affects access to knowledge, focusing especially on how the two forms of proximity interact. Employing patent citation data and using same-MSA and co-ethnicity as proxies for spatial and social proximity, respectively, we estimate a...

The development prospects of a poor country or region depend in part on its capacity for innovation. In turn, the productivity of its innovators, whom are often concentrated around urban centers, depends on their access to technological knowledge. The emigration of highly skilled individuals...