We study the implications of public information in a model where market prices convey information to relevant decision makers and the ‡uctuation of market prices is driven by multiple factors. Disclosure has a positive direct eect of providing new information and an indirect eect of changing the price informativeness. If disclosure is about a variable of which real decision makers are well informed, then the indirect eect is also positive, so that the direct eect is ampli…ed, leading to a positive overall eect on real e¢ ciency. If disclosure is about a variable that real decision markers care to learn much, then the indirect eect is negative and the direct eect is attenuated. Moreover, in markets which aggregate private information eectively, the negative indirect eect can dominate, so that disclosure can harm real e¢ ciency.