We study the implementation of social choice rules in environments with externalities. We prove the impossibility of implementing efficient and α-individually rational rules in dominant strategies. We prove that the α-core is implementable in Nash equilibrium under mild restrictions and it is...

We study the implementability of stable correspondences in marriage markets with externalities. We prove that, contrary to what happens in markets without externalities, no stable revelation mechanism makes a dominant strategy for the agents on one side of the market to reveal their preferences....