I model manufacturers competing through a retailer. I model two types of advertising that each firm can engage in: advertising that increases product differentiation and advertising that increases (possibly perceived) value of the product. While the two types of advertising result in...

I find that interconnection might cause the market to be less competitive, and might lead to an increase in the price firms charge for their product. Absent interconnection, firms compete for a consumer for two reasons. The first reason is to obtain revenue from selling the product to a consumer...

This article extends antitrust analysis to two-sided markets in which a virtual monopolist competes with local bricks-and-mortar dealers. The discussion examines the market power of an Internet market maker as well as an Internet matchmaker. The analysis shows that equilibrium in a two-sided...

We show that in many applied economic models, it is possible to reduce the dimensionality of the space of actions to what we call sufficient decisions. We find that for monopoly and oligopoly in multi-sided markets and multi-product markets, the market equilibrium can be transformed into an...

The U.S. credit card market is highly concentrated and highly profitable, two facts which have drawn scrutiny of its competitive practices. I study competition in this market by analyzing how lenders target and acquire new customers using direct-mail, their principal acquisition channel. I find...

This paper establishes how the classical facts characterizing a failure of competition in credit card lending during the 1980s are largely reversed in the decades following. Between 1990 and 2008 lenders' mark-ups decreased by 35 percent, profits shrank by 32 percent relative the average in...