Proportional approval voting: Difference between revisions
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The system disadvantages minority groups who share some preferences with the majority. In terms of [[tactical voting]], it is therefore highly desirable to withhold approval from candidates who are likely to be elected in any case, as with [[cumulative voting]] and the [[single non-transferable vote]].
PAV is strongly [[Monotonicity|monotonic]] and passes [[Independence of Irrelevant Ballots]] (IIB). However, it fails the [[Universally liked candidate criterion]] (ULC) and also [[Perfect representation|Perfect Representation In the Limit]] (PRIL), which is arguably a prerequisite for an approval method to be considered properly proportional.
== Example ==
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== Similar Systems ==
Both the [[Phragmén's Method]] and [[w:Sequential_proportional_approval_voting|Sequential Proportional Approval Voting]] are very similar systems invented in the early 1900s. [[Reweighted Range Voting]] is
Optimised PAV is the version of the method that allows any number of candidates to be elected according to the optimal candidate weights, rather than a fixed number with equal weight. It is not known if this method passes PRIL, but on the assumption that is does, it has been considered, along with [[COWPEA]], as a candidate method for the most accurately proportional approval method.<ref>{{Cite journal|last=Pereira|first=Toby|date=2023-05-17|title=COWPEA (Candidates Optimally Weighted in Proportional Election using Approval voting)|url=https://arxiv.org/abs/2305.08857|journal=arXiv}}</ref> Optimised PAV Lottery elects a fixed number of candidates with equal weight, using the candidate weights as probabilities, and it has parallels with COWPEA Lottery. If it does pass PRIL, then it would pass the four main Holy Grail criteria of PRIL, strong monotonicity, IIB and ULC, along with COWPEA Lottery.
== References ==
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