Surprisingly Popular Voting Recovers Rankings, Surprisingly!

Understand

The wisdom of the crowd has long become the de facto approach for eliciting information from individuals or experts in order to predict the ground truth.

• However, classical democratic approaches for aggregating individual \emph{votes} only work when the opinion of the majority of the crowd is relatively accurate.
• A clever recent approach, \emph{surprisingly popular voting}, elicits additional information from the individuals, namely their \emph{prediction} of other individuals' votes, and provably recovers the ground truth even when experts are in minority.
• This approach works well when the goal is to pick the correct option from a small list, but when the goal is to recover a true ranking of the alternatives, a direct application of the approach requires eliciting too much information.