We consider mechanism design environments with common knowledge of identicality that is in which agents commonly know that types are identically distributed without assuming that they or the designer would know the distribution. Under this assumption, we explore partial and full implementa¬tion, as well as robustness. First, we characterize the transfers which are incentive compatible under common knowledge of identicality, and provide necessary and sufficient conditions for partial imple¬mentation. We show that these conditions imply for all implementating mechanisms that a particular constraint holds on strategic externalitites. Second, within this constraint we characterize the condi¬tions under which full implementation is possible via direct mechanisms. We construct the loading transfer schemes and we show that these are the transfers which achieve full implementation whenever this is possible. Finally, we study the robustness properties of the implementing transfers with respect to misspecifications of agents’ preferences and with respect to lower orders beliefs in rationality.