Partially-honest Nash implementation: Characterization results

This paper studies implementation problems in the wake of a recent trend of implementation of non-consequentialist nature, which draws on the evidence taken from experimental and behavioral economics. Specifically, following the seminal works by Matsushima (2008) and Dutta and Sen (2009), the paper considers implementation problems with partially-honest agents, which presume that there is at least one individual in society who concerns herself with not only outcomes but also honest behavior at least in a limited manner. Given this setting, the paper provides a general characterization of Nash implementation with partially-honest individuals. It also provides the necessary and sufficient condition for Nash implementation with partially-honest individuals by mechanisms with some types of strategy-space reductions. As a consequence, it shows that in contrast to the case of the standard framework, the equivalence between Nash implementation and Nash implementation with strategy space reduction no longer holds.