In the presence of Pareto, non-dictatorship, full domain, and transitivity, an extremely weak independence condition disallows both anonymity and neutrality.

A feasible alternative x is a strong Condorcet winner if for every other feasible alternative y there is some majority coalition that prefers x to y. Let <InlineEquation ID="Equ1"> <EquationSource Format="TEX"><![CDATA[${\cal L}_{C}$]]></EquationSource> </InlineEquation> (resp., <InlineEquation ID="Equ2"> <EquationSource Format="TEX"><![CDATA[$\wp_{C})$]]></EquationSource> </InlineEquation> denote the set of all profiles of linear (resp., merely asymmetric) individual preference relations for which a strong Condorcet...</equationsource></inlineequation></equationsource></inlineequation>

Function g selects exactly k alternatives as a function of the preferences of n individuals. It cannot be manipulated by any individual, assuming that an individual prefers set A to B whenever A can be obtained from B by eliminating some alternatives and replacing each with a preferred...

The set of alternatives is infinite. If social welfare function f satisfies the Pareto criterion and there is a positive number β such that each pair of alternatives can be socially ordered without having to consult individual preference over a set with more than β alternatives then there are...

For four alternatives and an even number of individuals, we prove a conjecture in a companion paper: It is impossible for a social choice rule to satisfy all of (1) Pareto, (2) anonymity, (3) full domain, and (4) independence of some alternative, a relaxation of ArrowÕs IIA.

For a finite number of alternatives, in the presence of Pareto, non-dictatorship, full domain, and transitivity, an extremely weak independence condition is incompatible with each of anonymity and neutrality (Campbell and Kelly [2006]). This paper explores how those results are affected when...

Anonymity and neutrality conflict if the number of individuals is even and a single alternative is selected. Limited neutrality, anonymity, and monotonicity imply majority rule when the agenda is a two-element set.

The Condorcet rule on the domain of profiles at which there exists a unique Condorcet winner is the unique rule satisfying anonymity, neutrality, and strategy-proofness.

If only the strict part of social preference is required to be transitive then Independence of Irrelevant Alternatives implies that there is a coalition containing all but one individual that cannot force x to be socially ranked above y for at least half of the pairs of alternatives (x,y)

We characterize strategy-proof social choice procedures when choice sets need not be singletons. Sets are compared by leximin. For a strategy-proof rule g, there is a positive integer k such that either (i) the choice sets g(r) for all profiles r have the same cardinality k and there is an...