We study Bayesian mechanism design in situations where agents' information may be multi-dimensional, concentrating on mechanisms that lead to efficient allocations. Our main result is that a generalization of the well-known Vickrey-Clarke-Groves mechanism maximizes the planner's "revenue'' among...

It is known that majority voting among several individuals on logically interconnected propositions may generate irrational collective judgments. We generalize majority voting by considering quota rules, which accept each proposition if and only if the number of individuals accepting it exceeds...

In the theory of judgment aggregation on connected propositions, an important question remains open: Which aggregation rules are manipulable and which are strategy-proof? We define manipulability and strategy- proofness in judgment aggregation, characterize all strategy-proof aggregation rules,...

If each member of a group assigns a certain probability to a hypothesis, what probability should the collective as a whole assign? More generally, how should individual probability functions be merged into a single collective one? I investigate this question in case that the individual...

Many rent-sharing decisions in a society result from a bargaining process between groups of individuals (such as between the executive and the legislative branches of government, between legislative factions, between corporate management and shareholders, etc.). We conduct a laboratory study of...

A seller with two objects faces a group of bidders who are subject to budget constraints. The objects have common values to all bidders, but need not be identical and may be either complements or substitutes. In a simple complete information setting we show: (1) if the objects are sold by means...