Maximum Constrained Approval Bucklin: Difference between revisions

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(Initial page (haven't finalized the name yet))
 
m (Add EM post dates, and links to free riding wiki page.)
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Determining which voters to eliminate to maximize the support of a candidate subject to earlier constraints is relatively simple to do by linear programming, but hard to do by hand; FAB can't be counted entirely by hand.
Determining which voters to eliminate to maximize the support of a candidate subject to earlier constraints is relatively simple to do by linear programming, but hard to do by hand; FAB can't be counted entirely by hand.


What ended up as FAB was initially proposed in 2017<ref>{{cite web|url=http://lists.electorama.com/pipermail/election-methods-electorama.com/2017-January/001276.html|title=Bucklin multiwinner method|website=Election-methods mailing list archives}}</ref> and simplified in later that year<ref>{{cite web|url=http://lists.electorama.com/pipermail/election-methods-electorama.com/2017-September/001584.html|title=A simpler vote management-resistant Bucklin LP|website=Election-methods mailing list archives}}</ref>. The method detailed here has been further modified from the EM posts to resist Woodall free riding.
What ended up as FAB was initially proposed in 2017<ref>{{cite web|url=http://lists.electorama.com/pipermail/election-methods-electorama.com/2017-January/001276.html|title=Bucklin multiwinner method|website=Election-methods mailing list archives|date=2017-01-06}}</ref> and simplified in later that year<ref>{{cite web|url=http://lists.electorama.com/pipermail/election-methods-electorama.com/2017-September/001584.html|title=A simpler vote management-resistant Bucklin LP|website=Election-methods mailing list archives|2017-09-15}}</ref>. The method detailed here has been further modified from the EM posts to resist Woodall [[free riding]].


<<TBD, below this point, particularly the handling of epsilons>>
<<TBD, below this point, particularly the handling of epsilons>>
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* Droop proportionality criterion
* Droop proportionality criterion
* Invulnerability to Woodall free riding
* Invulnerability to [[free riding|Woodall free riding]]


FAB fails the following criteria:
FAB fails the following criteria:


* Weak invulnerability to Hylland free riding
* Weak invulnerability to [[free riding|Hylland free riding]]
* Monotonicity
* Monotonicity


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=== Monotonicity ===
=== Monotonicity ===
Like BTV, FAB fails the monotonicity criterion due to a lookahead problem<ref>{{cite web|url=http://lists.electorama.com/pipermail/election-methods-electorama.com/2018-February/001682.html|title=Path dependence monotonicity failure in BTV|website=Election-methods mailing list archives}}</ref>. However, FAB passes the two criteria above as long as the candidate to elect in a round is chosen (by some method) from the set of candidates with above Droop quota support for that round. Thus, it is possible that a variant that uses a yet unknown lookahead criterion instead of electing the candidate with the greatest support, could pass monotonicity.
Like BTV, FAB fails the monotonicity criterion due to a lookahead problem<ref>{{cite web|url=http://lists.electorama.com/pipermail/election-methods-electorama.com/2018-February/001682.html|title=Path dependence monotonicity failure in BTV|website=Election-methods mailing list archives|date=2018-02-18}}</ref>. However, FAB passes the two criteria above as long as the candidate to elect in a round is chosen (by some method) from the set of candidates with above Droop quota support for that round. Thus, it is possible that a variant that uses a yet unknown lookahead criterion instead of electing the candidate with the greatest support, could pass monotonicity.


== References ==
== References ==