Critics claim that patent screening is ineffective, granting low-quality patents that impose unnecessary social costs. We develop an integrated framework, involving patent office examination, fees, and endogenous validity challenges in the courts, to study patent screening both theoretically and...

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...

Using new data on citations to university patents and scientific publications, we study how geography affects university knowledge spillovers. Citations to patents decline sharply with distance and are strongly constrained by state borders. The effect of distance on citations to scientific...

We study how the market for innovation affects enforcement of patent rights. Conventional wisdom associates the gains from trade with comparative advantage in manufacturing or marketing. We show that these gains imply that patent transactions should increase litigation risk. We identify a new...

We study how the market for innovation affects enforcement of patent rights. Conventional wisdom associates the gains from trade with comparative advantage in manufacturing or marketing. We show that these gains imply that patent transactions should increase litigation risk. We identify a new...

We study how the market for innovation affects enforcement of patent rights. Conventional wisdom associates the gains from trade with comparative advantage in manufacturing or marketing. We show that these gains imply that patent transactions should increase litigation risk. We identify a new...

Using new data on citations to university patents and scientific publications, we study how geography affects university knowledge spillovers. Citations to patents decline sharply with distance up to about 150 miles and are strongly constrained by state borders. Distance also constrains...

This paper investigates the characteristics of litigated patents by combining for the first" time information about patent case filings from the U.S. district courts and detailed data from the" U.S. Patent and Trademark Office. We construct a series of indicators for the factors which the"...

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 very heterogeneous, being much higher for valuable...

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...