In light of research indicating that individual behavior may violate standard assumptions of rationality, we modify the standard model of preference aggregation to study the case in which neither individual nor collective preferences are required to satisfy transitivity or other coherence...

A unique bargaining solution satisfies restricted monotonicity, independence of irrelevant alternatives, independence of equivalent utility representations, and symmetry—the disagreement solution. It is also the unique bargaining solution that satisfies independence of irrelevant alternatives,...