The Gibbard-Satterthwaite Theorem on the manipulability of social-choice rules assumes resoluteness: there are no ties, no multi-member choice sets. Generalizations based on a familiar lottery idea allow ties but assume perfectly shared probabilistic beliefs about their resolution. We prove a...

From remarkably general assumptions, Arrow's Theorem concludes that a social intransitivity must afflict some profile of transitive individual preferences. It need not be a cycle, but all others have ties. If we add a modest tie-limit, we get a chaotic cycle, one comprising all alternatives, and...

A portrayal of the bill-to-law provisions of Latin American constitutions as extensive game forms shows presidential veto powers to be richer, more varied, and more regionally distinctive than hitherto appreciated. Small details and apparent redundancies are surprisingly consequential, the...

A version of the median-voter theorem holds for two-dimensional spatial models in which voters regard the two dimensions as economic goods or goodlike activities and in which the set of feasible outcomes is constrained by budget or technology. Although mathematically trivial, this fact has...

When we explicitly lay out all its steps, we find that the Paradox of Not Voting (since the chance of one vote's making a difference is about zero, why trouble to vote?) rests on a false but hitherto unremarked assumption about the institutional context of elections. My solution to the Paradox...