Oligopoly Theory and the Agreement Requirement
This chapter assesses the relationship between modern oligopoly theory and the meaning of the agreement requirement. Because competition law seeks to regulate oligopoly behavior and, moreover, to ground such regulation in modern economic understandings, it would seem to follow that, if the law's notion of agreement reflects economic substance, the agreement requirement would correspond to a core distinction drawn in oligopoly theory. As it turns out, that theory, which is an application of game theory (particularly, that of repeated games), does have an explicit notion of agreement. But this notion refers to binding agreements and thus is irrelevant for present purposes because competition law renders horizontal price-fixing agreements void ab initio.