Fallback voting (FV) is a voting method strongly related to Bucklin voting, invented by Brams and Sanvers. It is a ranked method which (with a slight modification) works by examining the 1st rank, and electing the candidate with the largest majority of voters ranking them 1st, if such a candidate exists. If no such candidate exists, then it examines both the 1st and 2nd ranks, and elects the candidate ranked either 1st or 2nd by the largest majority of voters. If none exists, the procedure continues to sequentially examine an additional rank at a time until either some candidate has the largest majority of ballots ranking them within the examined ranks, in which case they win, or until all ranks have been added in, at which point the candidate ranked on the most ballots wins.
Fallback voting is equivalent to the Expanding Approvals Rule in the single-winner case under certain conditions.
Remark 3 [...] For k = 1 and under linear orders for all but a subset of equally least preferred candidates applying the tweak in Remark 2 leads to the EAR [Expanding Approvals Rule] being equivalent to the Fallback voting rule (Brams and Sanver, 2009). 
References[edit | edit source]
- Brams, Steven; Sanver, Remzi (2006-12-07). "Voting Systems that Combine Approval and Preference". Archive ouverte HAL. Retrieved 2020-01-30.
- Aziz, Haris; Lee, Barton (2017-08-25). "The Expanding Approvals Rule: Improving Proportional Representation and Monotonicity". arXiv.org. p. 19. Retrieved 2020-01-30.