research in the areas of collusion and merger enforcement. Research relating to both collusion and mergers has made significant …-based measurement) and theoretical work in advancing our understanding of collusive and merger-related phenomena …

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 … surplus by using a completely myopic merger review policy that approves a merger today if and only if it does not lower …

We study optimal merger policy in a dynamic model in which the presence of scale economies implies that firms can … the period the merger is proposed. We also find that the ability to commit can lead to a significant welfare improvement …

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 …

Merger policy is the most active area of U.S. antitrust policy. It is now widely believed that merger policy must move … fundamentally affect merger analysis in two ways. First, innovation can dramatically affect the relationship between the pre-merger … marketplace and what is likely to happen if a proposed merger is consummated. Thus, innovation can fundamentally influence the …

guidelines reflect a substantial consensus on the appropriate template for merger assessment. Nevertheless, official protocols …

The challenge of effective merger enforcement is tremendous. U.S. antitrust agencies must, by statute, quickly forecast … estimating the price effects of mergers. We also describe how evidence from merger retrospectives can be used to evaluate the …

In this paper we propose a method to evaluate the effectiveness of U.S. horizontal merger policy and apply it to the … merger had little effect …

Merger control authorities may approve a merger based on a so-called 'efficiency defence'. An important aspect in … clearing mergers is that the efficiencies need to be merger-specific. Joint ventures, and in particular research joint ventures …

example, U.S. antitrust agencies lost several hospital merger challenges when evidence showed that a nontrivial fraction of …