In this paper we consider the exogenous indifference classes model of Barberá and Ehlers (2011) and Sato (2009) and analyze further the relationship between the structure of indifference classes across agents and dictatorship results. The key to our approach is the pairwise partition graph. We...

In this paper, we study implementation in "economic environments". It is shown that there is a dense subset of the set of preference profiles such that given an arbitrary social choice function, f and e 0, there exits another social choice function g, g within e of f uniformly, and g...

The paper considers a voting model where each voter's type is her preference. The type graph for a voter is a graph whose vertices are the possible types of the voter. Two vertices are connected by an edge in the graph if the associated types are "neighbors." A social choice function is locally...

In this paper, we revisit a long-standing question on the structure of strategy-proof and Pareto-efficient social choice functions (SCFs) in classical exchange economies (Hurwicz (1972)). Using techniques developed by Myerson in the context of auction-design, we show that in a specific...

We study the consequences of positive correlation of beliefs in the design of voting rules in a model with an arbitrary number of voters. We propose a notion of positive correlation, based on the likelihood of agreement of the k best alternatives (for any k) of two orders called TS correlation....

The paper proves the following result: every path-connected domain of preferences that admits a strategy-proof, unanimous, tops-only random social choice function satisfying a compromise property, is single-peaked. Conversely, every single-peaked domain admits a random social choice function...

The paper considers a voting model where each voter's type is her preference. The type graph for a voter is a graph whose vertices are the possible types of the voter. Two vertices are connected by an edge in the graph if the associated types are “neighbors.” A social choice function is...

We provide an axiomatic characterization of a family of criteria for ranking completely uncertain decisions. A completely uncertain decision is described by the set of all its consequences (assumed to be finite). Each of the criterions characterized can be thought of as assigning to all...

We study strategic voting after weakening the notion of strategy-proofness to Ordinal Bayesian Incentive Compatibility (OBIC). Under OBIC, truthelling is required to maximize the expected utility being computed with respect to the voter's prior beliefs and under the assumption that everybody...