The majority rule and the hierarchically dictatorial rule are both characterized when preferences are defined over two alternatives. The majority rule is characterized in terms of seven axioms. The hierarchically dictatorial rule is characterized in terms of six of these seven axioms and the...

The (relative) majority rule is a benchmark collective decision norm. This paper provides a simple characterization of the majority rule, for the two-alternative case, that relies on the following property: the choice prescribed by the rule to a group I of individuals must be the one that would...

The problem of aggregating preferences over two alternatives is considered. Three axioms are postulated: unanimity, reducibility (two divergent preferences can be replaced by their aggregation), and anonymity. It is shown that only twelve aggregation rules satisfy the three axioms: the majority...

When preferences are defined over two alternatives, the (relative) majority rule is characterized in terms of the four axioms U, P, I, and G. U is unanimity. P is the condition that the union of two unconcerned (that is, indifferent) groups of individuals creates an unconcerned group. I asserts...