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...

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 technological exhaustion. We first develop...

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...

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...

A model of patent infringement is developed to analyze the relationship between litigation and aspects of the legal environment such as the probability that the patent is found valid, the size of legal fees and their allocation across agents. Potential challengers first decide whether to...

Empirical estimates of the private value of patent protection are found for four technology area - computers, textiles, combustion engines, and pharmaceuticals - using new patent data for West Germany, 1953-1988. Patentees must pay to keep their patents in force. A dynamic stochastic discrete...

Comparisons of poverty rates are only rarely based on identical underlying definitions of welfare. The authors examine the sensitivity of poverty rates calculated from alternative definitions of consumption. They consider what theory can say about the direction of bias in comparisons and show...

Poverty comparisons--an increasingly important starting-point for welfare policy analysis--are almost always based on household surveys. Therefore they require that one be able to distinguish underlying differences in the populations being compared from sampling variation: standard errors must...

Poverty rates calculated on the basis of household consumption expenditures are routinely compared across countries and time. The surveys which underlie these comparisons typically differ in the types of food and non-food expenditures included, often in ways which are easily overlooked by...