The Value of Information for Groups

The paper examines the possibility of comparing di erent information structures in terms of informativeness, in the context of collective decision making. We set up a fairly general model of collective decision making through voting. Attention is restricted to groups in which members share a common objective. An information structure’s informativeness is measured by the expected aggregate value it o ers the group. Our first result shows that a comparison is possible in some cases, for any such like-minded group and any possible voting rule. Still, we show that the instances where such comparisons are possible are very limited. The set of information structures that can be compared is extended if one poses restrictions upon the profile of group members preferences or the voting rule. We apply some of our results to a model in which information is endogenous.