Collaborative Research: An Experimental Study on Collusion and Communication

从1890年的谢尔曼法案到今天，防止和发现竞争企业之间的共谋一直是反垄断和兼并政策的核心问题。 对于这种政策的设计，至关重要的是要了解什么时候可以预期串通可能和如何可以有效地劝阻。在过去，理论研究主要集中在理解合谋协议可以随着时间的推移而持续的机制上。相反，传闻证据表明，反托拉斯政策的主要影响是破坏企业达成串通协议的过程。人们对公司如何达成这种协议知之甚少，事实证明，从实地数据中查明这一点极为困难。因此，这是一个实验方法可以提供否则无法获得的见解的环境。 该项目包括一系列旨在研究企业如何达成合谋协议的实验。 它侧重于实验对象之间的明确沟通的作用，并试图确定有助于促进共谋的通信功能。所有的治疗都从一个初始阶段开始，在这个阶段没有可用的通信。 第二阶段是允许通信的阶段。 治疗方法在第二阶段允许的通信类型方面有所不同。这项研究的基本问题是，是否明确的沟通是必不可少的实现共谋。在这一主题的扩展，实验设计探讨了许多问题，沟通的哪些功能最重要的达成合谋的结果：* 理论表明，消息需要沟通的权变策略，但将简单的消息，只有关于当前的价格或数量就足够了吗？ * 如果只有一小部分被试最初能够遵循有效的共谋策略，那么他们与其他被试的互动是否会“感染”其他被试，并导致广泛的共谋？有些人是否系统地使用通信来达到欺骗目的？这会破坏“诚实”的玩家达成共谋协议的能力吗？* 允许重新协商沟通的可能性是否限制了应急信息的有效性？ * 复杂性如何影响沟通和共谋之间的关系？* 在真实的反垄断执法中，一项不完全针对和惩罚有关价格的沟通的政策能否有效地减少串通的发生率？更广泛的影响：该项目的结果对反垄断政策具有重要意义。 了解串通是如何产生的，就更容易确定稀缺的执法资源应集中在何处，以及哪些市场特征应被视为与评估合并的协调效应分析相关。我们的一些治疗方法包括分析受试者的信息内容，以确定哪些特定的短语可能产生共谋协议。 特别是，我们的实验使我们能够确定是否有针对性的执法发现这些类型的消息可以有效地打击勾结。研究结果还可以通过帮助划定合法商业活动和反竞争行为之间的界限，为企业之间的信息交换协议政策提供信息。

From the Sherman Act of 1890 through today, preventing and detecting collusion among competing firms has been a central issue for anti-trust and merger policy. For the design of such policy it is essential to understand when collusion can be expected to be likely and how it can be effectively discouraged. In the past theoretical research has focused primarily on understanding the mechanisms by which a collusive agreement can be sustained over time. In contrast, anecdotal evidence suggests that the primary impact of antitrust policy is to disrupt the process by which firms reach collusive agreements. Very little is known about how firms come to such agreements and it has proved extremely difficult to identify this from field data. This is therefore an environment in which an experimental approach can provide insights that would be otherwise unavailable. The project consists of a series of experiments designed to study how firms reach collusive agreements. It focuses on the role of explicit communication between experimental subjects for this purpose and seeks to identify the features of communication that help foster collusion. All treatments start with an initial phase where no communication is available. A second phase then follows where communication is allowed. The treatments vary in the type of communication that is allowed for this second phase. The study's fundamental question is whether explicit communication is essential for achieving collusion. Expanding on this theme, the experimental design explores numerous questions about what features of communication matter most for reaching collusive outcomes:* Theory suggests that messages need to communicate contingent strategies, but will simpler messages that are only about current prices or quantities suffice? * If only a small number of subjects can initially follow effective strategies for collusion, do their interactions with other subjects "infect" the rest of the population and lead to widespread collusion?* Do some individuals systematically use communication for deceptive purposes? Can this undermine the ability of 'honest' players to achieve collusive agreements? * Does allowing the possibility of communication to renegotiate limit the effectiveness of contingent messages? * How does complexity affect the relationship between communication and collusion? * Can a policy that that imperfectly targets and punishes communications about prices as in real anti-trust enforcement effectively reduce the incidence of collusion?Broader Impact: The results of this project have important implications for anti-trust policy. Understanding how collusion arises makes it easier to determine where scarce enforcement resources should be focused and which market characteristics should be considered relevant for the assessment of coordinated effects analysis in mergers. Some of our treatments involve analyzing the content of subject's messages to determine what specific phrases are likely to yield collusive agreements. In particular, our experiments allow us to determine whether targeting enforcement on finding these types of messages can effectively combat collusion. The results of the study can also inform policy towards information exchange agreements between firms by helping to delineate the boundary between legitimate business activity and anticompetitive behavior.