A social choice function may or may not satisfy a desirable property depending on its domain of definition. For the same reason, different conditions may be equivalent for functions defined on some domains, while not in other cases. Understanding the role of domains is therefore a crucial issue...

When members of a voting body exhibit single peaked preferences, pair-wise majority voting equilibria (Condorcet winners) always exist. Moreover, they coincide with the median(s) of the votersʼ most preferred alternatives. This important fact is known as the median voter result. Variants of it...

We provide characterizations of the set of outcomes that can be achieved by agenda manipulation for two prominent sequential voting procedures, the amendment and the successive procedure. Tournaments and super-majority voting with arbitrary quota q are special cases of the general sequential...

A decision-maker exhibits preference for flexibility if he always prefers any set of alternatives to its subsets, even when two of them contain the same best element. Desire for flexibility can be explained as the consequence of the agent’s uncertainty along a two-stage process, where he must...

We model the decision problems faced by the members of societies whose new members are determined by vote. We adopt a number of simplifying assumptions: the founders and the candidates are fixed; the society operates for a fixed number of periods and holds elections at the beginning of each period;...

When the members of a voting body exhibit single peaked preferences, majority winners exist. Moreover, the median(s) of the preferred alternatives of voters is (are) indeed the majority (Condorcet) winner(s). This important result of Duncan Black (1958) has been crucial in the development of...