Collaborative Research: New Applications of Dynamic Games with Asymmetric Information: Mergers, Capacity Discipline and Price Rigidity

本研究探讨了企业之间的信息不对称如何影响价格和消费者福利，以及如何改变反垄断政策来解释这些影响。目前，几乎所有的市场分析——无论是量化市场力量还是执行反事实分析——都假设完全信息，即所有公司都确切地知道其竞争对手的需求、边际成本和目标。然而，如果企业对自己的头寸了解得更多，那么他们可能会试图利用自己的定价或产能选择来影响竞争对手的信念，从而影响这些竞争对手未来的行为。一些简单的例子表明，即使是少量的不对称信息也会严重扭曲价格，并可能解释为什么合并后价格会大幅上涨；为什么即使菜单成本应该很低，价格却显得死板；还有，为什么一些行业，比如航空公司，似乎经历了运力约束时期。本研究将在理论、实证和方法上做出贡献。研究了具有非对称信息的多时期寡头垄断定价、竞价和产能选择博弈的非合谋马尔可夫完美贝叶斯均衡。该项目进一步发展计算方法来解决这种平衡，这往往需要解决非常大量的微分方程。相关代码将提供给其他研究人员。研究人员还使用包装消费品的扫描仪数据和航空市场的运力投资数据来测试和校准模型。此外，该项目还分析了实际并购中价格和企业行为的变化，以了解信息不对称是否可以解释为什么并购结果与反垄断当局批准并购时的预期存在显著差异。最后，这项研究训练了研究生，使他们能够在自己的研究中使用这些和其他技术。

This research investigates how asymmetric information between firms can affect prices and consumer welfare, and how antitrust policies might be changed to account for these effects. Currently almost all analyses of markets -- whether to quantify market power or perform counterfactuals -- assume complete information, in which all firms know the demand, the marginal costs and the objectives of their rivals exactly. However, if firms know more about their own positions, then they might try to use their pricing or capacity choices to influence what their rivals believe in order to affect how those rivals might behave in the future. Some simple examples suggest that even small amounts of asymmetric information can distort prices significantly, and potentially explain why prices rise significantly after mergers; why prices appear rigid even when menu costs should be small; and, why some industries, such as airlines, appear to go through periods of capacity discipline. This research will make theoretical, empirical and methodological contributions. The investigators first characterize non-collusive Markov Perfect Bayesian equilibria in multi-period oligopoly pricing, bidding and capacity choice games with asymmetric information. The project further develops computational methods to solve such equilibria, which often require solving very large numbers of differential equations. The associated code will be made available to other researchers. The investigators also test and calibrate the models using scanner data on consumer packaged goods and data on capacity investments in airline markets. In addition, the project analyzes changes in prices and firm behavior around actual mergers to understand whether asymmetric information can explain why outcomes were significantly different from what the antitrust authorities expected when the mergers were approved. Lastly, this research trains graduate students so that they can use these and other techniques in their own research.