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 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...

Sunk costs play a central role in antitrust economics, but are often misunderstood and mismeasured. I will try to clarify some of the conceptual and empirical issues related to sunk costs, and explain their implications for antitrust analysis. I will be particularly concerned with the role of...

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...