Value of information in competitive economies with incomplete markets

We study the value of information in a competitive economy in which agents trade in asset markets to reallocate risk. We characterize the kinds of information that allow a welfare improvement when portfolios can be freely reallocated. We then compare competitive equilibria before and after a change in information. We show that generically, if markets are sufficiently incomplete, the welfare effects are completely arbitrary: there typically exist changes in information that make all agents better off, or all agents worse off.