This chapter discusses different types of domain restrictions. We begin by analyzing various qualitative conditions on preference profiles. Value-restricted preferences (with single-peaked preferences as one of its subcases), limited agreement as well as antagonistic and dichotomous preferences...

Given a set of outcomes that affect the welfare of the members of a group, K.J. Arrow imposed the following five conditions on the ordering of the outcomes as a function of the preferences of the individual group members, and then proved that the conditions are logically inconsistent: • The...

Within the framework of the axiomatic approach three types of voting schemes are investigated according to the form in which the individual opinions about the alternatives are defined, as well as to the form of desired social decision. These types of rules are Social Decision Rules, Functional...

In the very general setting of Armstrong (1980) for Arrow's Theorem, I show two results. First, in an infinite society, Anonymity is inconsistent with Unanimity and Independence if and only if a domain for social welfare functions satisfies a modest condition of richness. While Arrow's axioms...

This chapter surveys the literature on strategy proofness from a historical perspective. While I discuss the connections with other works on incentives in mechanism design, the main emphasis is on social choice models.

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 explore the frontier between possibility and impossibility results by analyzing different combinations of "pro-socialness" and "consistency" conditions. This exercise delivers stronger versions of four classical impossibility theorems, and offers a thorough understanding of connections among...

Arrow's Impossibility Theorem is commonly understood to invoke a dictatorship that is somehow lurking within our voting arrangements. A well-recognized statement of the theorem is that "any constitution that respects transitivity, independence of irrelevant alternatives and unanimity is a...