We document the effects of a comprehensive set of US retail mergers. On average, prices increase by 1.5% and quantities decrease by 2.3%, with significant heterogeneity in outcomes across mergers. Price changes correlate with the screens codified in the Horizontal Merger Guidelines. Through a...

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...

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...

A study of the operation of Australia's merger policy over the last twenty-seven years can yield lessons for countries that are contemplating the introduction of their own merger policy. If it is to be used to enhance value, merger policy should provide that any possible increase in monopoly...

While the labor market implications of mergers have been historically ignored as "out of market" effects, recent actions by the Department of Justice (DOJ) place buyer market power (i.e., monopsony) at the forefront of antitrust policy. We develop a theory of multi-plant ownership and monopsony...

U.S. v. Microsoft and the related state suit filed in 1998 appear finally to have concluded. In a unanimous en banc decision issued in late June 2004, the D.C. Circuit Court of Appeals rejected challenges to the remedies approved by the District Court in November 2002. The wave of follow-on...

This paper provides the first quantitative economic models of pharmacy benefit management regulation. The price-theoretic models allow for various market frictions and imperfections including market power, coordination costs, tax distortions, and incomplete innovation incentives. A rigorous...

We hand-collect and standardize information describing all 3,055 antitrust lawsuits brought by the Department of Justice (DOJ) between 1971 and 2018. Using restricted establishment-level microdata from the U.S. Census, we compare the economic outcomes of a non-tradable industry in states...

Has the United States economy become less competitive in recent decades? One might think so based on a body of research that has rapidly become influential for antitrust policy. We explain that the empirical evidence relating to concentration trends, markup trends, and the effects of mergers...