On collusive behavior - models of cartel formation, organizational structure, and destabilization

This dissertation contributes to the theoretical literature on cartel formation, organizational structure, and destabilization in Cournot competitive markets. Cartel formation in Cournot competitive markets may take place as a sequential process even if the merger paradox applies. This conclusion was reached after giving up the assumption of symmetric information in cartel formation processes: it is assumed that outside firms are not informed about new cartel agreements and face a time lag by adjusting to changing behavior of some of the market participants. Furthermore, an extension to the standard cartel stability models is presented to capture the influence of communication and organizational structure in a cartel by modeling cartels as social networks. Despite the fact that communication in cartels is costly because contacts between members might be detected by antitrust authorities, it is shown that intensive contacts are possibly stabilizing within a cartel. Both aspects, the costs and benefits of communication in cartels, contribute to the players' valuation of collusion and therefore change cartel stability conditions. Additionally, this model accounts for the influence of leniency programs and fines. A theoretical explanation is given for differences between explicit and tacit collusion on the basis of this network model. Additionally, this dissertation examines whether collusive behavior might be deterred in vertical structures if dominant firms are allowed to apply specific discount schemes. It is shown that the profit maximizing behavior of a monopolistic upstream firm might lead to the deterrence of collusive behavior of downstream firms if the upstream firm is allowed to implement all-units discount schemes. All-units discounts, despite the fact that they are sometimes considered anticompetitive, possess welfare improving effects that are not generally shared by other pricing schemes.In der Arbeit werden verschiedene Aspekte kollusiven Verhaltens modelliert