Collusion et politique de la concurrence en information asymétrique

This article attempts to determine the optimal antitrust policy against price-fixing when competition authorities imperfectly observe firms' behaviour. By investigating or auditing on markets, authorities can detect collusion. We show that the strenght of investigations depends on the characteristics of the market, the cost of investigation, the severity of punishment and the degree of stability of the collusion. Moreover, it is shown that authorities always tolerate some degree of collusion as long as investigation is costly. The results of our paper allow us to establish some guidelines for antitrust policy.