A natural mechanism for eliciting rankings when jurors have favorites

- This paper analyzes the problem of a jury that must rank a set of contestants.
- Jurors may have friends among the contestants and therefore, may be biased.
- A necessary and sufficient condition for subgame perfect implementation is provided.
- A natural mechanism that is solvable by backward induction is shown.

We analyze the problem of a jury that must rank a set of contestants whose socially optimal ranking is common knowledge among jurors who may have friends among the contestants and may, therefore, be biased in their friends' favor. We show a natural mechanism that is finite and complete informational, with no simultaneous moves (i.e., it is solvable by backward induction), which implements the socially optimal ranking with subgame perfect equilibria.