The authors identify some fundamental conditions that a 'natural' mechanism should satisfy in exchange economies. First, they provide necessary and sufficient conditions for social choice correspondences to be implemented in Nash equilibria by natural mechanisms. Second, they show that the class...

Strategy-proofness, requiring that truth-telling is a dominant strategy, is a standard concept in social choice theory. However, the concept of strategy-proofness has serious drawbacks. First, announcing one's true preference may not be a unique dominant strategy, and using the wrong dominant...

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...

We conduct a two-stage game experiment with a non-excludable public good. In the first stage, two subjects choose simultaneously whether or not they commit to contributing nothing to provide a pure public good. In the second stage, knowing the other subject's commitment decision, subjects who...

What motivates subjects in their decision making is a lingering issue in public goods experiments. Using a nonlinear payoff function and a two-subject model, we create a one-toone correspondence between contributions and motivations, enabling us to isolate and identify the following three...