Weighted committees allow shareholders, party leaders, etc. to wield different numbers of votes or voting weights as they decide between multiple candidates by a given social choice method. We consider committees that apply scoring methods such as plurality, Borda, or antiplurality rule. Many...

In a market with indivisibilities, Roth and Postlewaite (1977) show that the (weak) core can suffer from instability problems, in the sense that groups of individuals might upset the equilibrium by recontracting among themselves. By contrast, the strong core is stable. Following the seminal...

This paper studies coalitional strategy-proofness of social choice correspondences that map preference profiles into sets of alternatives. In particular, we focus on the Pareto rule, which associates the set of Pareto optimal alternatives with each preference profile, and examine whether or not...

We study a social choice model with partially honest agents, and we show that strategy-proofness is a necessary and sufficient condition to achieve secure implementation. This result provides a behavioral foundation for the rectangularity property; and it offers as a by-product a revelation...

The revelation principle is a fundamental theorem in many economics fields. In this paper, we construct a simple labor model to show that a social choice function which can be implemented costly in Bayesian Nash equilibrium may not be truthfully implementable. The key point is the strategy cost...

In this paper we provide sufficient conditions for a social choice rule to be implementable in strong Nash equilibrium in the presence of partially honest agents, that is, agents who break ties in favor of a truthful message when they face indifference between outcomes. In this way, we achieve a...

We consider collective decision problems where some agents have private information about alternatives and others don't. Voting takes place under strategy-proof rules. Prior to voting, informed agents may or may not disclose their private information, thus eventually influencing the preferences...

The implementation problem is the problem of designing a mechanism (game form) such that the equilibrium outcomes satisfy a criterion of social optimality embodied in a social choice rule. If a mechanism has the property that, in each possible state of the world, the set of equilibrium outcomes...

We investigate the implementation of social choice functions (SCFs) from an epistemological perspective. We consider the possibility that in higher-order beliefs there exists an honest agent who is motivated by intrinsic preference for honesty as well as material interest. We assume weak...

We study dominant strategy implementation especially in economic environments. We first showthat in general environments, strategy-proofness and quasi-strong-non-bossiness together are necessary and sufficient for dominant strategy implementation via the associated direct revelationmechanism. We...