Competition authorities all over the world worry that integration between search engines (mainly Google) and publishers could lead to abuses of dominant position.  In particular, one concern is that of own-content bias, meaning that Google would bias its rankings in favor of the publishers it...

Although much research has been devoted to the impact of seller structure on market outcomes, considerably less is known about the influence of buyer structure. We examine the impact of buyer concentration on the pricing of a monopolist. Markets with both two and four buyers achieve prices well...

The increasing number of antitrust cases that affect more than one country calls for more active cooperation between competition authorities.  I analyse the impact of exchange of confidential information between two authorities deciding on a multinational merger.  The authorities want to clear...

We present a model in which a principal delegates the choice of project to an agent with different preferences. A project`s characteristics are verifiable once presented to the principal, but the principal does not know how many projects are available to the agent. The principal chooses the set...

An online platform makes a profit by auctioning an advertising slot that appears whenever a consumer visits its website.  Several firms compete in the auction, and consumers differ in their preferences.  Prior to the auction, the platform gathers data which is statistically correlated with...

We present a general Cournot model in which each firm may sell multiple quality-differentiated products. We use an upgrades approach, working not with the actual products, but instead with upgrades from one quality to the next. The properties of single-product Cournot models carry over to the...

This paper evaluates alternative strategic models of competition and market structure in online retailing, and makes comparisons with traditional retailing. Online consumers are less concerned than traditional consumers about spatial characteristics and more concerned about hidden quality...

The 1998 Competition Act represents a major change in the content and practice of competition policy in the United Kingdom, bringing it into line with European policy as practised under Articles 85 and 86. The paper presents an economic evaluation of the new provisions, and of the draft...

Edgworth's taxation paradox states that an excise tax can decrease the market price of a good.  This paper presents a new version of the paradox in which a tax reduces price because it attracts entry of additional firms into the market.  The paper also presents two new applications: (i) an...

Carbon leakage is a major concern for policymakers involved with environmental initiatives such as the European Union's emissions trading scheme and similar cap-and-trade proposals in the United States, Australia, and elsewhere.  This paper provides a framework for understanding the drives...