Cumulative innovation is central to economic growth. Do patent rights facilitate or impede such follow-on innovation …? This paper studies the effect of removing patent protection through court invalidation on the subsequent research related … to the focal patent, as measured by later citations. We exploit random allocation of judges at the U.S. Court of Appeal …

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 faster settlement agreements when patent rights are fragmented and …

We study the determinants of patent suits and their outcomes over the period 1978- 1999 by linking detailed information … from the U.S. patent office, the federal court system, and industry sources. The probability of being involved in a suit is … heterogeneous, being much higher for valuable patents and for patents owned by individuals and smaller firms. Thus the patent system …