We study approval voting in a setting with a fixed profile of individuals choices and variable societies. Four properties each linking choices made by a group of individuals to choices by its various subgroups are introduced, and are used for characterizing approval voting

We study simple majority rule from a perspective of coalitional decision makings. Four attrative properties each linking decisions by a group to decisions by its various coalitions are introduced, and are used for characterizing simple majority rule. Our characterization result provides an...

We provide characterizations of four new rules for individual decision-making under complete uncertainty. They are what we call the min-max rule, the max-min rule, the lexicographic min-max rule and the lexicographic max-min rule. These rules provide orderings of the sets of possible outcomes...