Most consumers benefit from a lowering of the required amount of aurous metal which jewelers must include in products sold as "gold." However, profits of producers of gold-plated adornments fall. The net welfare effect depends on whether the principal difference between consumers is their...

This paper analyses mergers between gas and electricity activities, a "conglomerate relationship" in the Commission lingo. We first review the paradigmatic case of the recent failed takeover on Endesa by Gas Natural in Spain. Then, we detail a model of imperfect competition combining four...

A patent is not a perfect protection against imitation. It only grants the patentholder the right to sue intruders once they have been identified. In order to identify an infringer, a patentholder must first monitor the market, and then react in case of infringement. His reaction may be to go to...

Intellectual property rights are legal constraints that limit entry in industries where incumbents are innovators. The set of legal constraints is the same for all industries, without considering that the externalities created by entry are not necessarily negative for the incumbent or that the...

Network activities typically involve collecting a good or service (such as electric utilities, phone services, and rail transportation) from many producers or distributing them to many users. Producers and users are often widely scattered, geographically. Close financial integration of networks...

This paper examines the use of bundling by a firm that sells in two national markets and faces entry by parallel traders. The firm can bundle its main product, - a tradable good- with a non-traded service. It chooses between the strategies of pure bundling, mixed bundling and no bundling. The...

"Information Disclosure in the Renewal of Patents" (with Claude Crampes), Les Annales d'Economie et Statistique, 49-50, pp 265-288, 1998. Reprinted in The Economics and Econometrics of Innovation, ed. Encaoua, Hall, Laisney, Mairesse, Kluwer academic publishers, 2000.