We generalize the canonical problem of Nash implementation by allowing agents to voluntarily provide discriminatory signals, i.e. evidence. Evidence can either take the form of hard information or, more generally, have differential but non-prohibitive costs in different states. In such...

We study full implementation with evidence in an environment with bounded utilities. We show that a social choice function is Nash implementable in a direct revelation mechanism if and only if it satisfies the measurability condition proposed by Ben-Porath and Lipman (2012). Building on a novel...

We introduce intention-based social preferences into a mechanism design framework with independent private values and quasilinear payoffs. For the case where the designer has no information about the intensity of social preferences, we provide conditions under which mechanisms which have been...

We introduce intention-based social preferences into mechanism design. We explore information structures that dier with respect to what is commonly known about the weight that agents attach to reciprocal kindness. When the designer has no information on reciprocity types, implementability of an...

We introduce intention-based social preferences into a Bayesian mechanism design framework. We first show that, under common knowledge of social preferences, any tension between material efficiency, incentive compatibility, and voluntary participation can be resolved. Hence, famous impossibility...

Ostracism is practiced by virtually all societies around the world as a means of enforcing cooperation and excluding members who show anti-social behaviors or attitudes. In this paper, we use a public goods experiment to study whether groups choose to implement an institution that allows for the...

Strategy-proofness, requiring that truth-telling be a dominant strategy, is a standard concept in social choice theory. However, this concept has serious drawbacks. In particular, many strategy-proof mechanisms have multiple Nash equilibria, some of which produce the wrong outcome. A possible...

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...

This paper introduces excluding outlier voters (EOV) as a general mechanism for revealing true preferences in social choices, and for discouraging voters from strategic voting and manipula-tion. This mechanism is general in that it can be implemented with any voting system. The paper...