Approval voting and Shapley ranking
Working paper
Issue number:
2018/12
Series:
CORE Discussion Papers
Publisher:
Université Catholique de Louvain - Center for Operations Research and Econometrics
Year:
2018
Approval voting allows voters to list any number of candidates. Their scores are obtained by
summing the votes cast in their favor. Fractional voting instead follows the One-person-onevote
principle by endowing voters with a single vote that they may freely distribute among
candidates. In this paper, we show that fairness requires the distribution of votes to be uniform.
Uniform fractional voting corresponds to Shapley ranking that was introduced to rank wines as
the Shapley value of a cooperative game with transferable utility. Here we analyze the
properties of these "ranking games" and provide an axiomatic foundation to Shapley ranking.
We also analyze Shapley ranking as a social welfare function and compare it to approval
ranking.