Sequential unanimity voting rules for binary social choice

We consider a group of voters that needs to decide between two candidates. In this setting, M-winning coalition rules are characterized by neutrality and strategy-proofness (Moulin, 1983). Their practical implementation motivates the introduction of sequential unanimity rules. We develop algorithms that transform a given M-winning coalition rule into an equivalent sequential unanimity rule and vice versa. The sequential unanimity rules that are constructed present computational advantages compared to their M-winning counterparts. The analysis extends to the full preference domain. Since M-winning coalition rules are closely related to strong and proper simple games, the analysis is relevant to this strand of the game-theoretic literature as well.