We consider an optimal mechanism design problem with several heterogenous objects and interdependent values. We characterize ex post incentives using an appropriate monotonicity condition and reformulate the problem in such a way that the choice of an allocation rule can be separated from the...

Collective choice problems on sets in <InlineEquation ID="Equ1"> <EquationSource Format="TEX"> ${\frak R}_+^n$</EquationSource> </InlineEquation> arise naturally in economics. Such problems have been extensively studied both in the theory of revealed preferences (Peters and Wakker, 1991) and in axiomatic bargaining theory under the assumption of convexity. However, our knowledge of...</equationsource></inlineequation>