We investigate the causal effect of patent rights on cumulative innovation, using large-scale data that approximate the patent universe in its technological and economic variety. We introduce a novel instrumental variable for patent invalidation that exploits personnel scarcity in post-grant...

We study the blocking effect of patents on follow-on innovation by others. We posit that follow-on innovation requires freedom to operate (FTO), which firms typically obtain through a license from the patentee holding the original innovation. Where licensing fails, follow-on innovation is...

This paper develops a two-industry model of R&D. A monopolist supplier sells an intermediate good to an oligopolistic buyer industry where firms compete in quantity and quality-enhancing R&D. The supplier can contribute to downstream product improvements by creating spillover knowledge which...

Using a newly constructed panel dataset of German enterprises, I estimate R&D and capital investment equations for the time period from 1990 to 1994. Simple accelerator specifications indicate considerable sensitivity of R&D and investment to cash flow for relatively small firms. Much of this...