This survey examines recent developments in economic research relating to antitrust, paying specific attention to research in the areas of collusion and merger enforcement. Research relating to both collusion and mergers has made significant advances in the last twenty years. With respect to...

We augment the multi-market collusion model of Bernheim and Whinston (1990) by allowing for firm entry into, and exit from, individual markets. We show that this gives rise to a new mechanism by which a cartel can sustain a collusive agreement: Collusion at the extensive margin whereby firms...

This paper studies an economy in which incomplete markets and strong complementarities interact to generate path dependent aggregate output fluctuations. An economy is said to be path dependent when the effect of a shock on the level of aggregate output is permanent in the absence of future...

This paper investigates the dynamic behavior of an economy with multiple Nash equilibria. The first part of the paper analyzes an abstract game exhibiting multiple equilibria. A history dependent selection criterion is proposed which induces correlated behavior in equilibrium even though agents...

Firms tend to compete more aggressively in financial distress; the intensified competition in turn reduces profit margins, pushing themselves further into distress and adversely affecting other firms. To study such feedback and contagion effects, we incorporate strategic competition into a...

This paper provides an algorithm for computing Markov Perfect Nash Equilibria (Maskin and Tirole, 1988a and b) for dynamic models that allow for heterogeneity among firms and idiosyncratic (or firm specific) sources of uncertainty. It has two purposes. To illustrate the ability of such models to...

This paper uses an aggregative games framework to predict consumer welfare when market structure is endogenously determined. Our main results characterize mergers whose synergies reduce consumer welfare by inducing rivals to exit. The conditions under which such mergers arise are broad,...

We construct a fully specified extensive form game that captures competitive markets with adverse selection. In particular, it allows firms to offer any finite set of contracts, so that cross-subsidization is not ruled out. Moreover, firms can withdraw from the market after initial contract...

This paper studies quantitative implications of model economies that exhibit multiple equilibria. The goal is to assess two interrelated issues. First, do economies with multiple equilibria have falsifiable predictions? Second, is identification possible in economies that exhibit multiple...

The standard Beckerian analysis of marriage market equilibrium assumes that allocation within marriage implements agreements made in the marriage market. This paper investigates marriage market equilibrium when allocation within marriage is determined by bargaining in marriage and compares that...