We develop a simple model of competition for the market that shows that, contrary to the Arrow view, endogenous entry threat in a market induces the average rm to invest less in R&D and the incumbent leader to invest more than the average rm. We test these predictions with a Tobit model based on a unique dataset and survey for the German manufacturing sector (the Mannheim Innovation Panel). In line with our predictions, endogenous entry threats perceived by the rms reduce R&D intensity for the average rm, but not for an incumbent leader. Moreover, the size of the rms and their patent stocks, proxy for the protection of IPRs, are positively related to R&D intensity. These results hold after a number of robustness tests with instrumental variables.JEL{Classi cation: O31, O32