The authors analyze incomplete long-term contracts when buyers incur relationship-specific set-up costs and sellers choose product or service quality that is not verifiable to third parties. If set-up costs are observable, the first-best outcome can be achieved even though contracts cannot...

We analyze an overlapping-generations model of duopolistic competition in the presence of consumer switching costs. Competition for established buyers is continually intermingled with competition for new, uncommitted buyers. In equilibrium the firm with attached customers typically specializes...

The authors analyze horizontal mergers in Cournot oligopoly. They find general conditions under which such mergers raise price, and show that any merger not creating synergies raises price. The authors develop a procedure for analyzing the effect of a merger on rivals and consumers and, thus,...

We study the welfare economics of probabilistic patents that are licensed without a full determination of validity. We examine the social value of instead determining patent validity before licensing to downstream technology users, in terms of deadweight loss (ex post) and innovation incentives...

We study the effects of changes in the ownership or productive assets in a concentrated industry. Using a Cournot model, we analyze (1) investment by an oligopolist, (2) the sale of capital goods by one oligopolist to another, and (3) stock market purchases, whereby one firm acquires a partial...

We propose that this measure ("UPP") be used as an indicator of the merger’s likely unilateral effects. Joseph Farrell (FTC) & Carl Shapiro (DOJ).