Antitrust populists increasingly call on the government to “break up big tech.” But antitrust enforcers would face heavy evidentiary burdens if they sought to break a company up on the premise that a long-consummated merger was unlawful from the outset and should have been blocked years ago....

I present the following proposal: information revealed during non-cartel investigations by competition law enforcement authorities, such as evaluation of M&As or investigation of monopolization (dominance) conduct, should be directly used to investigate and prosecute cartels. Currently, in...

I present the following proposal: information revealed during non-cartel investigations by competition law enforcement authorities, such as evaluation of M&As or investigation of monopolization (dominance) conduct, should be directly used to investigate and prosecute cartels. Currently, in...

An increasing body of empirical evidence is documenting trends toward rising concentration, profits, and markups in many industries around the world since the 1980s. Two major criticisms of these studies is that concentration and market shares are poorly measured at the national industry level...

An increasing body of empirical evidence is documenting trends toward rising concentration, profits, and markups in many industries around the world since the 1980s. Two major criticisms of these studies is that concentration and market shares are poorly measured at the national industry level...

This is a survey of the economic principles that underlie antitrust law and how those principles relate to competition policy. We address four core subject areas: market power, collusion, mergers between competitors, and monopolization. In each area, we select the most relevant portions of...

The aim of this paper is to describe in detail a set of newly developed indicators of the quality of competition policy, Competition Policy Indexes, or CPIs. The CPIs measure the deterrence properties of a competition policy in a jurisdiction, where for competition policy we mean the antitrust...

We estimate the deterrence effects of European Commission (EC) merger policy instruments over the 1990-2009 period. Our empirical results suggest that phase-1 remedies uniquely generate robust deterrence as – unlike phase-1 withdrawals, phase-2 remedies, and preventions – phase-1 remedies...

We model merger control procedures as a process of sequential acquisition of information in which mergers can be cleared after a first phase of investigation. We find that the enforceability of clearance decisions at the end of the first phase is unattractive to the extent that it prevents the...