We investigate the structure of fuzzy aggregation rules which, for every permissible profile of fuzzy individual preferences, specify a fuzzy social preference. We show that all fuzzy aggregation rules which are strategyproof and satisfy a minimal range condition are dictatorial. In other words,...

A general model of judgment aggregation is presented in which judgments on propositions are not binary but come in degrees. The primitives of the model are a set of propositions, an entailment relation, and a “triangular norm” which establishes a lower bound on the degree to which a...

Imagine that everyone in a group chooses a real number and then these numbers are combined to produce a group number. Suppose that when everyone moves strictly closer to some individual’s number, the group number either stays where it is or moves closer to this number. We call this the...

We consider the problem of aggregating individual approval ballots into one collective approval ballot. An approval ballot is simply a subset of a given set of alternatives. An individual may approve of as many alternatives as he or she wishes. Each approval is counted as a vote. We show that if...