The concept of the Condorcet winner has become central to most electoral models in the political economy literature. A Condorcet winner is the alternative preferred by a plurality in every pairwise competition; the notion of a k-winner generalizes that of a Condorcet winner. The k-winner is the...

We present simple and direct arguments to characterize strongly group strategy-proof social choice functions whose range is of cardinality two. The underlying society is of arbitrary cardinality, and agents can be indifferent among alternatives.

When a counter-proposal is made to an initiative to change the Swiss constitution, the citizenry makes three binary majority choices: the initiative versus the status quo, the initiative versus the counter-proposal, and the status quo versus the counterproposal as a tie-breaker. If there is a...

Politicians, CEOs and various other types of dictators make social choices that influence both their own and others' welfare. When a dictator's preferred alternative differs from recipients', it is unclear which preferences they aggregate and how they determine this set of admissible...

We derive a very general ("Janus") money demand function, which reflects backward and forward-looking habit formation. This generality offers an explanation for the breakdown of money-demand functions and policy relevance of monetary aggregates. Integrating our Janus money demand into a...

Consider a setting in which individual strict preferences need to be aggregated into a social strict preference relation. For two alternatives and an odd number of agents, it follows from May’s Theorem that the majority aggregation rule is the only one satisfying anonymity, neutrality, and...

Can the exchange rate be stationary in levels? We answer this question in the negative by proving an impossibility theorem, built upon the absence of arbitrage in international economies. We establish the sufficient conditions for the exchange rate to not be a stationary process in levels, and...

Gibbard and Satterthwaite have shown that the only single-valued social choice functions (SCFs) that satisfy nonimposition (i.e., the function's range coincides with its codomain) and strategyproofness (i.e., voters are never better off by misrepresenting their preferences) are dictatorships. In...

Some economists in the Austrian tradition interpret the Arrow Impossibility Theorem (AIT) as support for their laissez-faire standpoint. They presume that the AIT cannot be applied in market settings, but in the context of voting, it adds weight to their arguments against the possibility of...

We study a voting model with partial information in which the evaluation of social welfare must be based on information about agents' top choices plus qualitative background conditions on preferences. The former is elicited individually, while the latter is not. The social evaluator is modeled...

Condorcet domains are sets of preference orders such that the majority relation corresponding to any profile of preferences from the domain is acyclic. The best known examples in economics are the single-peaked, the single-crossing, and the group separable domains. We survey the latest...

The conditions of strong Condorcet winner consistency and strong Condorcet loser consistency are, in essence, universally accepted. However, there are many situations in which they are silent. The weak counterparts of these properties suffer from the fatal flaw that a weak Condorcet winner can...