This paper analyzes the coordination challenge a partial cartel faces when payoff asymmetries between potential cartel insiders and potential cartel outsiders are large. We introduce two experimental treatments: a standard treatment where a complete cartel can be supported in a Nash equilibrium and a modified treatment where a complete cartel and a partial cartel can both be supported in a Nash equilibrium. To assess the role of communication both treatments are additionally run with a “chat option,” yielding four treatments in total. Our results show that subjects frequently reject the formation of partial cartels in the modified treatments. In all treatments with communication subjects are more likely to form complete cartels than partial cartels. The implications of these results are important for antitrust: payoff asymmetries between cartel members and outsiders may jeopardize the formation of partial cartels. Yet complete cartels may be formed instead, if institutional mechanisms with frequent communication are used to form cartels.

本文分析了当潜在卡特尔内部人和潜在卡特尔外部人之间的回报不对称很大时，部分卡特尔面临的协调挑战。我们介绍了两种实验处理方法：一种标准处理方法，在纳什均衡中可以支持完全卡特尔，另一种是修改处理，其中完全卡特尔和部分卡特尔都可以在纳什均衡中得到支持。为了评估沟通的作用，这两种治疗方法都另外运行“聊天选项”，总共产生四种治疗方法。我们的结果表明，受试者经常拒绝在修改后的治疗中形成部分卡特尔。在所有与交流的治疗中，受试者比部分卡特尔更有可能形成完整的卡特尔。这些结果的含义对反垄断很重要：卡特尔成员与外来者之间的回报不对称可能会危及部分卡特尔的形成。然而，如果使用频繁沟通的制度机制来形成卡特尔，则可能会形成完整的卡特尔。