We identify necessary and sufficient conditions for the choice set from every subset A of a (finite) universal set X to coincide with the top cycle in A of some fixed tournament on X.

We identify necessary and sufficient conditions for the choice set from every subset A of a (finite) universal set X to coincide with the top cycle in A of some fixed tournament on X.

We reconsider the following cost-sharing problem: agent i = 1, ...,n demands a quantity xi of good i; the corresponding total cost C(x1, ..., xn) must be shared among the n agents. The Aumann-Shapley prices (p1, ..., pn) are given by the Shapley value of the game where each unit of each good is...

We examine the maximal-element rationalizability of choice functions with arbitrary domains. While rationality formulated in terms of the choice of greatest elements according to a rationalizing relation has been analyzed relatively thoroughly in the earlier literature, this is not the case for...

We examine the maximal-element rationalizability of choice functions with arbitrary do-mains. While rationality formulated in terms of the choice of greatest elements according to a rationalizing relation has been analyzed relatively thoroughly in the earlier litera-ture, this is not the case...

A group of agents participate in a cooperative enterprise producing a single good. Each participant contributes a particular type of input; output is nondecreasing in these contributions. How should it be shared? We analyze the implications of the axiom of Group Monotonicity: if a group of...

We analyze an alternative to the standard rationalizability requirement for observed choices by considering non-deteriorating selections. A selection function is a generalization of a choice function where selected alternatives may depend on a reference (or status quo) alternative in addition to...

We identify conditions under which preferences over sets of consumption opportunities can be reduced to preferences over bundles of "commodities". We distinguish ordinal bundles, whose coordinates are defined up to monotone transformations, from cardinal bundles, whose coordinates are defined up...