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,...

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 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 paper presents a new method for estimating discrete games based on bounds of conditional choice probabilities. The method does not require solving the game and is scalable to models with many firms and many discrete decisions. We apply the method to study merger effects on firm entry and...

We examine merging firms' additions and removals of products for a sample of 66 mergers across a wide variety of consumer packaged goods markets. We find that mergers lead to a net reduction in the number of products offered by merging firms. Merging firms tend to both drop and add products at...