R&D Spillovers, Innovation, and Entry

The paper extends a theoratical framework to analyze the impact of R&D spillovers on entry and the resulting equilibrium market structure. It is shown that the degree of spillovers plays a fundamental role on the number of firms entering the market, their R&D activities, and social welfare. The analysis suggests that social welfare is maximized at some intermediate degree of spillovers. The policy implication of this result is that neither complete protection of intellectual property right nor lax enforcement of patent laws is socially optimal