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 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 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...

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