We consider a general economy, where agents have private information about their types. Types can be multi-dimensional and potentially interdependent. We show that, if the realized frequency of types (the exact number of agents for each type) is common knowledge, then a mechanism exists, which...

We say that a social choice rule is implementable with (small) transfers if one can design a mechanism whose set of equilibrium outcomes coincides with that specified by the rule but the mechanism allows for (small) ex post transfers among the players. We then show in private-value environments...