This study details the location patterns of R&D labs in the U.S., but it differs from past studies in a number of ways. First, rather than looking at the geographic concentration of manufacturing firms (e.g., Ellison and Glaeser, 1997; Rosenthal and Strange, 2001; and Duranton and Overman, 2005), the...

This working paper supersedes WP 12-22, WP 11-42, and WP 10-33. We employ a unique data set to examine the spatial clustering of private R&D labs, and, using patent citations data, we provide evidence of localized knowledge spillovers within these clusters. Jaffe, Trajtenberg, and Henderson...