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Social choice and electoral systems
A joint Politics and Economics series

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Multiwinner approval voting,^[1] sometimes also called approval-based committee (ABC) voting,^[2] refers to a family of multi-winner electoral systems that use approval ballots. Each voter may select ("approve") any number of candidates, and multiple candidates are elected.

Multiwinner approval voting is an adaptation of approval voting to multiwinner elections. In a single-winner approval voting system, it is easy to determine the winner: it is the candidate approved by the largest number of voters. In multiwinner approval voting, there are many different ways to decide which candidates will be elected.

^ Aziz, Haris; Gaspers, Serge; Gudmundsson, Joachim; Mackenzie, Simon; Mattei, Nicholas; Walsh, Toby (2014-07-11). "Computational Aspects of Multi-Winner Approval Voting". arXiv:1407.3247 [cs.GT].
^ Aziz, Haris; Brill, Markus; Conitzer, Vincent; Elkind, Edith; Freeman, Rupert; Walsh, Toby (2017). "Justified representation in approval-based committee voting". Social Choice and Welfare. 48 (2): 461–485. arXiv:1407.8269. doi:10.1007/s00355-016-1019-3. S2CID 8564247.