effect on the performance of domestic firms relative to their foreign competitors, by stimulating domestic innovation. We … examine the stylized facts regarding environmental expenditures and innovation in a panel of manufacturing industries. We find …

interplay of these two localized externalities and their impact on regional innovation. We examine MSA-level patent data during … the period 1975-2000 and find that innovation output is higher where large and small labs coexist. The finding is robust …