Stepwise models of technological progress described by Philippe Aghion and his co-authors (1997, 2001, 2005) capture the incentives of firms to innovate in order to escape competition and the disincentives from sharing profits with other technological leaders. The models yield intuitively...

Political candidates, legislators and academics have made proposals to separate services provided by dominant digital platforms from activities that rely on these services. Although the platforms have different economic and technical characteristics, common themes that motivate these proposals...

Committing to prices that result in rationing may be more profitable than setting market-clearing prices if customers must make sunk investments to enter the market. Rationing is ex post inefficient, but it gives more surplus to lower-value customers who are the marginal consumers the...

There is widespread dissatisfaction with existing antitrust enforcement. The European Union has enacted comprehensive legislation to address perceived antitrust limitations, and several proposals to amend US antitrust laws have followed its lead. Most of the actual and proposed laws target firms...

We analyze the central economic issues raised by U.S. v Microsoft. Network effects and economies of scale in applications programs created a barrier to entry for new operating system competitors, which the combination of Netscape Navigator and the Java programming language potentially could have...

The Microsoft antitrust case focused public attention on the role of antitrust enforcement in preserving the forces of innovation in high-technology markets. Traditionally, regulators focused on whether companies artificially hiked prices or reduced output. Now, they're increasingly likely to...

We ask under what conditions transmission contracts increase or mitigate market power. We show that the allocation process of transmission rights is crucial. In an efficiently arbitraged uniform price auction generators will only obtain contracts that mitigate their market power. However, if...