The theoretical literature on platforms and network effects predicts that the initial growth and takeoff of a platform crucially depends on the market’s expectations of the future installed base. This paper tests this claim, reporting on a field experiment in which invitations to join a newly...

Digital platforms are increasingly the subject of regulatory scrutiny. In comparison to multiple competitors, a single platform may increase consumer welfare if network effects are large or may decrease welfare due to higher prices or reduction in platform variety. We study the net effect of...

This Chapter provides a survey of the economics literature on multi-sided platforms with particular focus on competition policy issues, including market definition, mergers, monopolization, and coordinated behavior. It provides a survey of the general industrial organization theory of...

We study the importance of discretion in antitrust enforcement by analyzing the response of asset prices to the sudden accession of Theodore Roosevelt to the presidency. During McKinley's term in office the largest wave of merger activity in American history occurred, and his administration did...

In this paper we review issues relating to antitrust and competition in health care markets. The paper begins with a brief review of antitrust legislation. We then discuss whether and how health care is different from other industries in ways that might affect the optimality of competition. The...

Open borders imply systems competition. This paper studies the implications of systems competition for the national competition rules. It is shown that an equilibrium where all countries retain their antitrust laws does not exist, since abolishing this law makes it possible for a single country...

This paper presents an empirical analysis of the relationship between patenting, innovation, and federal antitrust enforcement towards firms in the manufacturing sector. I examine whether the likelihood of antitrust litigation is influenced by patent histories and R&D expenditures, after...

U.S. v. Microsoft and the related state suit filed in 1998 appear finally to have concluded. In a unanimous en banc decision issued in late June 2004, the D.C. Circuit Court of Appeals rejected challenges to the remedies approved by the District Court in November 2002. The wave of follow-on...

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....

In this article, I explain the inadequacy of our current state of knowledge regarding the effectiveness of antitrust policy towards mergers. I then discuss the types of data that one must collect in order to be able to perform an analysis of the effectiveness of antitrust policy. There are two...