Sufficient and Necessary Conditions for Information to have Social Value in Pure Exchange
扩展并统一了关于公共信息社会价值和无交易条件的已有结论，给出了单期和两期情形下信息具有社会价值的充分必要条件，发现公共信息的社会价值比以往认为的更强。
ABSTRACT This paper extends, corrects, and unifies earlier statements concerning the social value of public information as well as the no‐trading conditions in pure exchange. Sufficient and necessary conditions are provided for both the single‐period and two‐period cases in a postsignal trading model. The social value of information is shown to be closely linked to the allocational efficiency of the market, the degree of homogeneity of prior beliefs, and of information structures, the time‐additivity of preferences, and the efficiency of endowments. We conclude that the case in favor of public information is much stronger than previously suggested.