Since the passage of the Interstate Commerce Act (1897) and the Sherman Act (1890), regulation and antitrust have operated as competing mechanisms to control competition. Regulation produced cross-subsidies and favors to special interests, but specified prices and rules of mandatory dealing....

We test whether firms use incompatibility strategically, using data from ATM markets. High ATM fees degrade the value of competitors' deposit accounts, and can in principle serve as a mechanism for siphoning depositors away from competitors or for creating deposit account differentiation. Our...

I discuss the antitrust suit brought by the U.S. Department of Justice against Visa and MasterCard in 1998. Banks that issue Visa cards are free to also issue MasterCard cards, and vice versa, and many banks issue the cards of both networks. However, both Visa and MasterCard had rules...

We develop a model in which firms set impersonal salary levels before matching with workers. Salaries fall relative to any competitive equilibrium while profits rise by almost as much, implying little inefficiency. Furthermore, the best firms gain the most from the system while wages become...

The 2010 Department of Justice and Federal Trade Commission Horizontal Merger Guidelines lay out a new standard for assessing proposed mergers in markets with differentiated products. This new standard is based on a measure of ``upward pricing pressure,'' (UPP) and the calculation of a ``gross...

Governments rescue private companies partly to prevent other firms from gaining excessive market power. However, if failing firms exit, new entry may limit remaining firms' market power if there are potential entrants who can be as effective competitors as the firms leaving the market. We...

This paper develops a framework for estimating preferences in two-sided matching markets with non-transferable utility using only data on observed matches. Unlike single-agent choices, matches depend on the preferences of other agents in the market. I use pairwise stability together with a...

In The Antitrust Paradox, Robert Bork viewed most mergers as either competitively neutral or efficiency enhancing. In his view, only mergers creating a dominant firm or monopoly were likely to harm consumers. Bork was especially skeptical of oligopoly concerns resulting from mergers. In this...

For voters with "social" preferences, the expected utility of voting is approximately independent of the size of the electorate, suggesting that rational voter turnouts can be substantial even in large elections. Less important elections are predicted to have lower turnout, but a feedback...

Members of a patent pool agree to use a set of patents as if they were jointly owned by all members and license them as a package to other firms. Regulators favor pools as a means to encourage innovation: Pools are expected to reduce litigation risks for their members and lower license fees and...