In a framework allowing infinitely many individuals, I prove that coalitionally strategyproof social choice functions satisfy tops only. That is, they depend only on which alternative each indvidual prefers the most, not on which alternative she prefers the second most, the third, \dots, or the...

In the very general setting of Armstrong (1980) for Arrow's Theorem, I show two results. First, in an infinite society, Anonymity is inconsistent with Unanimity and Independence if and only if a domain for social welfare functions satisfies a modest condition of richness. While Arrow's axioms...