We study how fragmentation of patent rights ('patent thickets') and the formation of the Court of Appeal for the Federal Circuit (CAFC) affected the duration of patent disputes, and thus the speed of technology diffusion through licensing. We develop a model of patent litigation which predicts...

Cumulative innovation is central to economic growth. Do patent rights facilitate or impede such follow-on innovation? This paper studies the causal effect of removing patent protection through court invalidation on subsequent research related to the focal patent, as measured by later citations....