Algorithms, especially those based on artificial intelligence, play an increasingly important role in our economy. They are used by market participants to make pricing, output, quality, and inventory decisions; to predict market entry, expansion, and exit; and to predict regulatory moves. In a...

We examine the role of private information on the impact of vertical mergers. A vertical merger can improve the information that is available to an upstream monopolist because, after the merger, the monopolist can observe the cost of its downstream merger partner. In the pre-merger world,...

The importance of economics to the analysis and enforcement of competition policy and law has increased tremendously in the developed market economies in the past forty years. In younger and developing market economies, competition law itself has a history of twenty to twenty-five years at most...

The "worst opinion" of the title is not the appellate affirmance in United States v. AT&T, which put the final end to the government's challenge to the merger of AT&T and Time Warner. It was the trial court's fundamental ruling at the close of the bench trial, rejecting the government's claims....

A growing number of policymakers and scholars are calling for tougher rules to curb corporate acquisitions. But these appeals are premature. There is currently little evidence to suggest that mergers systematically harm consumer welfare. More importantly, scholars fail to identify alternative...

One of the most striking and undertheorized aspects of fields that commercialize patented technologies is the dynamic interplay of structural forces pushing toward consolidation. Of course, technological industries are complex ecosystems featuring numerous players of different sizes along the...

While the Comcast/TWC merger is significant in size, it doesn’t give rise to any plausible theory of anticompetitive harm under modern antitrust analysis. Comcast and TWC don’t compete directly for subscribers in any relevant market; in terms of concentration and horizontal effects, the...

This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

We consider differentiated duopolists facing symmetric linear demands and using Cobb-Douglas technologies with two inputs: a monopolized input and a competitively supplied input. Unlike with fixed-proportions technologies, a merger between the input monopolist and either firm can reduce welfare....

The importance of merger retrospectives as a way to assess competition policy is well-recognized. Yet there have been few retrospectives – none that we are aware of for any recent merger – that examine the accuracy of the predictions made by economic models used in the antitrust...