In this paper, we study implementation in "economic environments". It is shown that there is a dense subset of the set of preference profiles such that given an arbitrary social choice function, f, and 0, there exists another social choice function, f, within of f uniformly and implementable in...

In this paper we introduce a new definition of strategy-proofness for multi-valued social choice correspondences. We prove two Gibbard-Satterthwaite type results for strategy-proof social choice correspondences. These results show that allowing multiple outcomes as social choices will not...