technological exhaustion. We first develop an index of patent ‘quality’ using detailed information on patents in the U.S. in seven …We analyse the determinants of the decline in measured research productivity (the patent/R&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 …

heterogeneous, being much higher for valuable patents and for patents owned by individuals and smaller firms. Thus the patent system …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 …