Cartel Formation and Cartel Stability - Experiments on the Role of the Leniency Rule and with open Communication

对卡特尔的起诉是世界各国反垄断机构工作的重要组成部分，因为卡特尔会严重损害社会福利。最近，许多反垄断机构引入了宽大的规则，以破坏现有卡特尔的稳定，并阻碍新卡特尔的形成。从经验上看，很难判断这些措施是否成功，因为研究人员无法观察到运作中的卡特尔的（数量）。因此，需要对该课题进行实验研究。然而，以往的实验研究在许多方面简化了决策框架，因此很难从实验结果中得出宽大规则对真实卡特尔的影响。该项目的主要目标是分析当反垄断机构作为积极参与者参与实验时宽大政策的有效性。这对于结果的外部有效性至关重要。最重要的是，一个积极的反垄断机构的存在允许通信发生，而不一定导致卡特尔的形成，并允许自由的文本通信。先前关于宽大规则的研究没有区分明确的价格协议和无害话题的沟通，在控制的情况下，沟通的决定被自动解释为卡特尔的形成。然而，真实公司的真实员工还是会时不时地遇到其他公司的员工，比如在交易会的背景下。此外，尽管律师事务所不会因为谈论与市场行为或价格无关的话题而被起诉，但即使是这样的交流也可能通过产生信任而促进串通。先前关于沟通对卡特尔形成和稳定的作用的研究没有考虑与反垄断机构的互动或宽大规则的引入。该项目还有三个进一步的目标。首先，我们将分析卡特尔的形成和稳定性如何受到一种更灵活的沟通方式的影响，在这种方式下，如果集团作为一个整体不一致同意沟通，公司的子集团也可以进行沟通。其次，我们将明确分析在确定的头目免于罚款的情况下，与积极的反垄断当局进行的卡特尔起诉。最后，我们计划测试当消费者剩余实际上以消费者的角色支付给实验参与者时，与目前的做法相反，市场行为是否会发生变化。

Cartel prosecution is an important part of the work of antitrust authorities all around the world, because cartels can severely harm social welfare. Recently, many antitrust authorities introduced leniency rules to destabilize existing cartels and hinder the formation of new ones. Empirically, it is difficult to judge the success of these measures, because researchers cannot observe (the number of) functioning cartels. Therefore, experimental studies on the topic are needed. However, previous experimental studies have simplified the decision framework in many aspects so that it is hard to draw conclusions about the effects of the leniency rule on real cartels from their results.The main objective of the project is to analyze the effectiveness of leniency policies when the antitrust authority is included as an active player in the experiment. This is crucial with respect to the external validity of the results. Most importantly, the presence of an active antitrust authority allows communication to take place without necessarily resulting in cartel formation and allows for free text communication. Previous studies on the leniency rule did not distinguish explicit price agreements from communication about harmless topics and in case of a control, the decision to communicate was automatically interpreted as the formation of a cartel. However, real employees of real firms meet the employees of other firms anyway from time to time, for example in the context of trade fairs. Moreover, while according to the law firms cannot be prosecuted for talking about topics that are unrelated to market conduct or prices, even such communication may facilitate collusion by generating trust. Previous studies on the role of communication for cartel formation and stability did not consider the interaction with an antitrust authority or the introduction of a leniency rule. The project has three further objectives. First, we will analyze how cartel formation and stability is affected by an even more flexible approach to communication where subgroups of firms can also communicate if the group as a whole does not unanimously agree to communicate. Second, we will explicitly analyze cartel prosecution with active antitrust authorities when an identified ringleader is exempt from fine. Finally, we plan to test whether market conduct changes when, in contrast to current practice, the consumer surplus is actually paid to experimental participants in the role of consumers.