We investigate the effect of a vertical merger on downstream firms' ability to collude in a repeated game framework. We show that a vertical merger has two main effects. On the one hand, it increases the total collusive profits, increasing the stakes of collusion. On the other hand, it creates...

Platforms often use fee discrimination within their marketplace (e.g., Amazon, eBay, and Uber specify a variety of merchant fees). To better understand the impact of marketplace fee discrimination, we develop a model that allows us to determine equilibrium fee and category decisions that depend...

In a two-country international trade model with oligopolistic competition, we study the conditions on market structure and trade costs under which a merger policy designed to benefit domestic consumers is too tough or too lenient from the viewpoint of the foreign country. Calibrating the model...

We study the gains from trade in a model with oligopolistic competition, heterogeneous firms and innovation, and provide a formula to decompose the mechanism. The new insight we provide is that market concentration can be a welfare-relevant feature of market power above and beyond markup...

The U.S. and EU Merger Guidelines strongly emphasize the relevance of the "ease of entry" argument in merger evaluations. Up to now, very little is known empirically about how mergers affect entry and exit, and the resulting number of firms in the markets. We empirically test this aspect of...

We study upstream horizontal mergers and their potential efficiency gains. We show that an upstream horizontal merger can give rise to two efficiency-enhancing effects when firms trade through two-part tariffs. It increases R&D investments and decreases wholesale prices when downstream...