It is known that, in Condorcet's classical jury model, the proportion of jurors supporting a decision is not a significant indicator of that decision's reliability: the probability that a particular majority decision is correct given the majority size depends only on the absolute margin between the majority and the minority, and is invariant under changes of the proportion in the majority if th...

In sequential majority voting, preferences are aggregated by a sequence of pairwise comparisons (also called an agenda) between candidates. The result of each comparison is determined by a weighted majority vote between the agents. In this paper we consider the situation where the agents may not have revealed all their preferences. This is common in reallife settings, due to privacy issues or a...

Preferences can be aggregated using voting rules. We consider here the family of rules which perform a sequence of pairwise majority comparisons between two candidates. The winner thus depends on the chosen sequence of comparisons, which can be represented by a binary tree. We address the difficulty of computing candidates that win for some trees, and then introduce and study the notion of fair...

Special majority voting is usually defined in terms of the proportion of the electorate required for a positive decision. This note reassesses that definition, and proposes an alternative. The proposal is to define special majority voting in terms of the absolute margin between the majority and the minority required for a positive definition. It is shown that if we use special majority voting f...

In judgment aggregation, unlike preference aggregation, not much is known about domain restrictions that guarantee consistent majority outcomes. We introduce several conditions on individual judgments su¢ cient for consistent majority judgments. Some are based on global orders of propositions or individuals, others on local orders, still others not on orders at all. Some generalize classic soci...

This is an analysis of strategic voting under the qualified majority rule. Existing formal analyses of the plurality rule predict the complete coordination of strategic voting: A strict interpretation of Duverger’s Law. This conclusion is rejected. Unlike previous models, the popular support for each option is not commonly certain. Agents base their vote on both public and private signals of po...