Partially-honest Nash implementation: a full characterization

A partially-honest individual is a person who follows the maxim, "Do not lie if you do not have to" to serve your material interest. By assuming that the mechanism designer knows that there is at least one partially-honest individual in a society of n ≥ 3 individuals, a social choice rule (SCR) that can be Nash implemented is termed partially-honestly Nash implementable. The paper o§ers a complete characterization of the n-person SCRs that are partially-honestly Nash implementable. It establishes a condition which is both necessary and su¢cient for the partially-honest Nash implementation. If all individuals are partially-honest, then all SCRs that satisfy the property of unanimity are partially-honestly Nash implementable. The partially-honest Nash implementation of SCRs is examined in a variety of environments. JEL classification: C72; D71.