In this paper we consider a model in which agents have complete information about their neighbours and, possibly, incomplete information about the rest of the economy. We consider two different informational frameworks. In the first, agents do not have priors about what is going on in the rest of the economy. In the second, agents are supposed to have priors about the unknown characteristics. We present a mechanism which any social choice correspondence satisfying monotonicity and no veto powet in both informational settings for every possible prior thus requiring little knowledge from the point of view of the designer of the information possesed by agents about the economy.