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...

Market definition and market power are central features of competition law and practice but pose serious challenges. On one hand, market definition suffers decisive logical infirmities that render it infeasible, unnecessary, and counterproductive, and the practice of stating market power...

Over the last years, several reports highlighted the market power of very large online platforms that are gatekeeping intermediaries between businesses and consumers, and the difficulty for classic competition policy tools to deal effectively with anti-competitive practices in these platforms....

The last couple of years have seen an increasing interest in critical loss analysis, both, in academia and in practice. This development is documented by various research papers, high-level exchanges between antitrust experts as well as an increasing number of case decisions – in the United...

The last couple of years have seen an increasing interest in critical loss analysis, both, in academia and in practice. This development is documented by various research papers, high-level exchanges between antitrust experts as well as an increasing number of case decisions which make use of...

Worldwide, the overwhelming majority of large horizontal mergers are cleared by antitrust authorities unconditionally. The presumption seems to be that efficiencies from these mergers are sizeable. We calculate the compensating efficiencies that would prevent a merger from harming consumers for...

Economic analysis of competition regulation is most developed in the domain of horizontal mergers, and modern agency guidelines reflect a substantial consensus on the appropriate template for merger assessment. Nevertheless, official protocols are understood to rest on a problematic market...

Antitrust enforcement in technology industries can be challenging: historical market information may have limited relevance, market shares may be unstable, and new entrants can be highly disruptive. Both the Federal Trade Commission and the Department of Justice have acknowledged the rigors of...

Because market definition is frequently outcome determinative, it is both a central and contested part of antitrust litigation. Recognition of business methods known as multisided platforms presents the challenge of whether and how to incorporate their characteristically interconnected groups...