We study optimal merger policy in a dynamic model in which the presence of scale economies implies that firms can reduce costs through either internal investment in building capital or through mergers. The model, which we solve computationally, allows firms to invest or propose mergers according...

We analyze the optimal dynamic policy of an antitrust authority towards horizontal mergers when merger proposals are endogenous and occur over time. Approving a currently proposed merger will affect the profitability and welfare effects of potential future mergers, the characteristics of which...

Concentration-based screens for horizontal mergers, such as those employed in the US DOJ and FTC Horizontal Merger Guidelines, play a central role in merger analysis. However, the basis for these screens, in both form and level, remains unclear. We show that there is both a theoretical and an...

Elzinga/Hogarty inflow/outflow analysis is a mainstay of geographic market definition in antitrust analysis. For example, U.S. antitrust agencies lost several hospital merger challenges when evidence showed that a nontrivial fraction of local patients traveled outside the local community for...

Health care report cards - public disclosure of patient health outcomes at the level of the individual physician and/or hospital - may address important informational asymmetries in markets for health care, but they may also give doctors and hospitals incentives to decline to treat more...

Reclassification risk is a major concern in health insurance. We use a rich dataset with individual-level information on health risk to empirically study one possible solution: dynamic contracts. Empirically, dynamic contracts with one-sided commitment substantially reduce the reclassification...

We study the effects of antitrust policy in industries with continual innovation. A more protective antitrust policy may have conflicting effects on innovation incentives, raising the profits of new entrants, but lowering those of continuing incumbents. We show that the direction of the net...

In this paper, we provide a conceptual framework for understanding the phenomenon of exclusive dealing, and we explore the motivations for and effects of its use. For a broad class of models, we characterize the outcome of a contracting game in which manufacturers may employ exclusive dealing...

Tied sales have a long history of scrutiny under the antitrust laws of the United States. The primary basis for the condemnation of this practice has been the court's belief in what has come to be known as the "leverage theory" of tying: that is, that tying provides a mechanism whereby a firm...

A number of recent papers have studied the relationship between price and market structure in the deregulated airline industry through a cross-sectional analysis of city-pair markets. Yet, while interesting, several potential difficulties underlie the inferences drawn in these analyses. In this...