Toronto

In two-sided matching markets with interdependent values the matching outcome has infor-mational content that can be used to challenge a proposed match after it has been announced to the agents. In such environments, exempli\u85ed by the student-college admission problem, we introduce a notion of posterior group stability and, when student preferences are homo-geneous, construct a modi\u85ed serial dictatorshipmechanism that implements group stable matchings. We further discuss the robustness of our notion of stability and examine e ¢ ciency and monotonicity properties of modi\u85ed serial dictatorship