A social choice function is robustly implementable if there is a mechanism under which the process of iteratively eliminating strictly dominated messages leads to outcomes that agree with the social choice function for all beliefs at every type profile. In an interdependent value environment...

We provide a characterization of virtual Bayesian implementation in environments satisfying no-total-indifference. A social choice function in such environments is virtually Bayesian implementable if and only if it satisfies incentive compatibility and a condition we term virtual monotonicity....

Politicians may pander to public opinion and may renounce undertaking beneficial long-term projects. To alleviate this problem, we introduce a triple mechanism involving political information markets, reelection threshold contracts, and democratic elections. An information market is used to...

"Strategy-proofness" is one of the axioms that are most frequently used in the recent literature on social choice theory. It requires that by misrepresenting his preferences, no agent can manipulate the outcome of the social choice rule in his favor. The stronger requirement of "group...

We revisit the incompatibility of anonymity and neutrality in single-valued social choice. We first analyze the irresoluteness outlook these two axioms together with Pareto efficiency impose on social choice rules and deliver a method to refine irresolute rules without violating anonymity,...

This paper examines possibility of partial ex post implementation under general utility functions which is not necessarily differentiable or quasi-linear with respect to money. We deal with an interdependent-value model in which there are two agents, two alternatives and each agent receives more...

We consider the problem of allocating a single object to the agents with payments. Agents have preferences that are not necessarily quasi-linear. We characterize the class of rules satisfying pairwise strategy-proofness and non-imposition by the priority rule. Our characterization result remains...

We study a cardinal model of voting with three alternatives where voters' von Neumann Morgenstern utilities are private information. We consider voting protocols given by two-parameter scoring rules, as introduced by Myerson (2002). For these voting rules, we characterize symmetric Bayes Nash...

Serizawa [3] characterized the set of strategy-proof, individually rational, no exploitative, and non-bossy social choice functions in economies with pure public goods. He left an open question whether non-bossiness is necessary for his characterization. We will prove that non-bossiness is...

In a general interdependent preference environment, we characterize when two payoff types can be distinguished by their rationalizable strategic choices without any prior knowledge of their beliefs and higher order beliefs. We show that two payoff types are strategically distinguishable if and...