Eliciting Socially Optimal Rankings from Biased Jurors: Two Juror Case

I extend the results of Amorós (2009) to the two juror case. Amorós looked at the environment where a jury of 3 or more had to report a ranking of contestants. There exists a true ranking which is known to all the jurors, but is not known nor verifiable by the social planner. The social planner’s social choice rule is to figure out the true ranking from the jurors. The jurors can be biased over contestants, so I use partially-impartial and partially-indifferent preferences to get implementation. I show that it is impossible to subgame perfect implement in the two juror case with restrictions only on partially-impartial preferences, but I show that with restrictions on partially-impartial and partially-indifferent preferences we can get implementation, and how large is the Universe in which implementation occurs. I also show that the simple two-turn extensive form game, where one juror suggests a ranking, then the second juror suggests a ranking dependent on the previous juror’s suggestion, is an optimal mechanism for Subgame perfect implementation in this problem. Finally, Nash implementation sufficient results are characterized. JEL Classification: D78, C70