In response to recent work on the aggregation of individual judgments on logically connected propositions into collective judgments, it is often asked whether judgment aggregation is a special case of Arrowian preference aggregation. We argue the op- posite. After proving a general impossibility...

The problem of social choice is studied on a domain with countably many individuals. In contrast to most of the existing literature which establish either non-constructive possibilities or approximate (i.e. invisible) dictators, we show that if one adds a continuity property to the usual set of...

This chapter briefly reviews the present state of judgment aggregation theory and tentatively suggests a future direction for that theory. In the review, we start by emphasizing the difference between the doctrinal paradox and the discursive dilemma, two idealized examples which classically...

We consider collective decision problems where some agents have private information about alternatives and others don't. Voting takes place under strategy-proof rules. Prior to voting, informed agents may or may not disclose their private information, thus eventually influencing the preferences...

Consider the following principle regarding the performance of collective choice rules. "If a rule selects alternative x in situation 1, and alternative y in situation 2, there must be an alternative z, and some member of society whose appreciation of z relative to x has increased when going from...

This paper reports on the results of a series of experimental laboratory elections. The novelty of the design allows me to study both coordination failures and coordination efficiency in a repeated-game, divided majority setting. I assess and compare the performance of three voting mechanisms,...

We axiomatize the anti-plurality rule by anonymity, neutrality, reinforcement, and new axioms, that is, averseness and bottoms-only. Averseness is a weaker axiom than faithfulness, and bottoms-only is an opposite axiom of tops-only. Thus, we do not apply the characterization of a scoring social...

Arrow's original proof of his impossibility theorem proceeded in two steps: showing the existence of a decisive voter, and then showing that a decisive voter is a dictator. Barbera replaced the decisive voter with the weaker notion of a pivotal voter, thereby shortening the first step, but...

We say that a social choice function is sensitive to collective change if whenever all inputs change, the outcome necessarily changes. Then, we prove that a social choice function is sensitive to collective change if and only if it is dictatorial. This provides a new interpretation of the...