A jury must provide a ranking of contestants (students applying for scholarships or Ph. D. programs, gymnasts in a competition, etc.). There exists a true ranking which is common knowledge among the jurors, but it is not verifiable. The socially optimal rule is that the contestants be ranked...

This paper studies Nash implementation when the outcomes of the mechanism can be renegotiated among the agents but the planner does not know the renegotiation function that they will use. We characterize the social objectives that can be implemented in Nash equilibrium when the same mechanism...

We propose a multidimensional spatial model of political competition where the advertising campaign aims at influencing the weights that voters’ preferences assign to different political issues. The campaign strategies will move the vote of those voters who lack of partisan identification. The...