We argue that when externalities such as pollution are nonexcludable, agents must be compelled to participate in a “mechanism” to ensure a Pareto-efficient outcome. We survey some of the main findings of the mechanism-design (implementation-theory) literature – such as the Nash...

An important result in convex analysis is the duality between a closed convex set and its support function. We exploit this duality to develop a novel geometric approach to mechanism design. For a general class of social choice problems we characterize the feasible set, which is closed and...