Patent Enforcement and Subsequent Innovation

Abstract

How does patent enforcement affect subsequent innovation? I exploit patent infringement litigation in the United States to analyze the effect of patent enforcement on cumulative innovation. The results imply that subsequent innovation increase after a case is filed in a court. While there is a strong increase during the litigation period, the relative effect size decreases in the years following the closure of the case. Further results imply that signals about the value of the patent and reductions in asymmetric information are particular driver of the increase in follow-on innovation. Although there is a general positive effect, subsequent innovation show a low degree of novelty and are close to the litigated patents in terms of technological proximity and general similarity.

Keywords: Patent enforcement, Patent infringement litigation, Subsequent innovation, Patent citations, Intellectual property rights

JEL Classification: K11, K41, L24, O30, O31, O32, O34