We analyse the determinants of the decline in measured research productivity (the patent/Ramp;D ratio)using panel data on manufacturing firms in the U.S. for the period 1980-93. We focus on three factors: the level of demand, the quality of patents, and technological exhaustion. We first develop...

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...

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. Patents and Trademark Office. A series of indicators is constructed for the factors which the...

This paper investigates the effect of the threat and occurrence of patent litigation on the private value of patent protection. Potential challenges are introduced into a renewal model as a factor in patentee decisions as to whether a patent is worth maintaining. The model yields testable...