Value of information in competitive economies with incomplete markets

We study the value of public information in competitive economies with incomplete markets. We show that generically the welfare effect of a change in the information available prior to trading can be in any direction: There exist changes in information that make all agents better off and changes for which all agents are worse off. In contrast, for any change in information, a Pareto improvement is feasible, that is, attainable by a planner facing the same informational and asset market constraints as agents. In this sense, the response of competitive markets to changes in information is typically not socially optimal.