Ex Post Regret and the Decentralized Sharing of Information
研究企业通过投资决策透露私人信息后可能产生的事后遗憾，定义了一种理性预期均衡，发现即使没有事后遗憾，投资从众行为也可能低效，且均衡可能不存在。
Firms reveal private information about the value of investment through their investment decisions. As a consequence they may have ex post regret once they see other firms' investments. We define a notion of rational expectations equilibrium for games which imposes a “no-regret” property. In this equilibrium, all firms make the same investment decision, but despite the absence of ex post regret, the investment herd can be inefficient. In addition equilibrium might not exist. We introduce a notion of probabilistic existence, and identify conditions under which, if the number of firms is large, enough information comes out so that investment herds are first-best efficient with high probability, and equilibrium exists with high probability.Journal of Economic LiteratureClassification Numbers: C7, D8.