[EM] A few papers on election science I'd like to point out to y'all

[Richard Lung]

BTV "known on this list for some time now as a superior option to STV." 
Other systems, including BTV are not so regarded by organisations, like 
the PRSA and Electoral Reform Society for well over a century. Not to 
mention Fair Votes USA.

Richard Lung.


On 04/02/2018 19:18, Jameson Quinn wrote:
> Yes, I believe that many of these references refer to what is 
> essentially BTV, which has been known on this list for some time now 
> as a superior option to STV. I'm happy that it's now in the 
> literature, and don't really care about naming/precedence.
>
> It's my experience that many prop-rep voting methods can be expressed 
> in terms of an STV backend. PLACE, Dual Member Proportional, many MMP 
> variants, etc. can all be seen as just adding options (such as 
> overlapping seats for MMP and DMP, biproportionality for DMP and 
> PLACE, and partial delegation for PLACE) on top of STV. You could 
> therefore create new versions of all of the above by replacing STV 
> with BTV. I think this would be a small step up — but not worth the 
> additional difficulty of explanation, in a world that's more used to STV.
>
> 2018-02-04 12:22 GMT-05:00 Kristofer Munsterhjelm 
> <km_elmet at t-online.de <mailto:km_elmet at t-online.de>>:
>
>     On 01/29/2018 02:43 PM, Arthur Wist wrote:
>
>         Hello,
>
>         Sorry in advanced for the huge load of information all at
>         once, but I think you'll highly likely find the following
>         quite interesting:
>
>         On how people misunderstood the Duggan-Schwartz theorem:
>         https://arxiv.org/abs/1611.07105
>         <https://arxiv.org/abs/1611.07105> - Two statements of the
>         Duggan-Schwartz theorem
>         https://arxiv.org/abs/1611.07102
>         <https://arxiv.org/abs/1611.07102> -  Manipulability of
>         consular election rules
>
>         EVERYTHING here:
>         https://scholar.google.com/citations?user=ssb0yjUAAAAJ&sortby=pubdate
>         <https://scholar.google.com/citations?user=ssb0yjUAAAAJ&sortby=pubdate>
>
>         Some key highlights from that last link above:
>
>         https://arxiv.org/abs/1708.07580
>         <https://arxiv.org/abs/1708.07580> - Achieving Proportional
>         Representation via Voting [ On which a blog post exists:
>         https://medium.com/@haris.aziz/achieving-proportional-representation-2d741871e78
>         <https://medium.com/@haris.aziz/achieving-proportional-representation-2d741871e78>.
>         Better than STV and STV derivatives in all criteria? You decide! ]
>
>
>     >From a cursory look at the latter, that looks like Bucklin with a
>     STV-style elect-and-reweight system. I wrote some posts about a
>     vote-management resistant version of Bucklin at
>     http://lists.electorama.com/pipermail/election-methods-electorama.com/2016-December/001234.html
>     <http://lists.electorama.com/pipermail/election-methods-electorama.com/2016-December/001234.html>
>     and
>     http://lists.electorama.com/pipermail/election-methods-electorama.com/2017-September/001584.html
>     <http://lists.electorama.com/pipermail/election-methods-electorama.com/2017-September/001584.html>,
>     and found out that the simplest way of breaking a tie when more
>     than one candidate exceeds a Droop quota is nonmonotonic.
>
>     The simplest tiebreak is that when there are multiple candidates
>     with more than a quota's worth of votes (up to the rank you're
>     considering), you elect the one with the most votes. This can be
>     nonmonotone in th following way:
>
>     Suppose in the base scenario, A wins by tiebreak, and B has one
>     vote less at the rank q, so A is elected instead of B. In a later
>     round, say, q+1, E wins. Then suppose a few voters who used to
>     rank A>E decides to push E higher.
>
>     Then B wins at rank q. If now most of the B voters vote E at rank
>     q+1, it may happen that the deweighting done to these voters
>     (since they got what they wanted with B being elected instead of
>     A) could keep the method from electing E.
>
>     E.g. A could be a left-wing candidate, B be a right-wing
>     candidate, and E a center-right candidate. In the base scenario, A
>     wins and then the B voters get compensated by having the
>     center-right candidate win. But when someone raises E, the method
>     can't detect the left wing support and so the right-wing candidate
>     wins instead. Afterwards, the right-wing has drawn weight away
>     from E (due to E not being a perfect centrist, but instead being
>     center-right), and so E doesn't win.
>
>     Achieving monotonicity in multiwinner rules is rather hard; it's
>     not obvious how a method could get around the scenario above
>     without considering later ranks.
>
>     I'm not sure if rank-maximality solves the problem above. If it
>     doesn't, then the above is an example of CM failure but not RRCM
>     failure.
>
>     See also
>     http://lists.electorama.com/pipermail/election-methods-electorama.com/2012-January/094876.html
>     <http://lists.electorama.com/pipermail/election-methods-electorama.com/2012-January/094876.html>
>     and
>     http://lists.electorama.com/pipermail/election-methods-electorama.com/2012-February/095188.html
>     <http://lists.electorama.com/pipermail/election-methods-electorama.com/2012-February/095188.html>
>     for another Bucklin PR method that seemed to be monotone.
>
>     It's also unknown whether Schulze STV is monotone, though it seems
>     to do much better than IRV-type STV in this respect. And I'd add
>     that there's yet another (very strong) type of monotonicity not
>     mentioned in the paper as far as I could see. Call it "all-winners
>     monotonicity" - raising a winner on some ballot should not replace
>     any of the candidates on the elected council with anyone ranked
>     lower on that ballot.
>
>     (There's a result by Woodall that you can't have all of LNHelp,
>     LNHarm, mutual majority and monotonicity. Perhaps, due to the
>     difficulty of stopping the monotonicity failure scenario above,
>     the equivalent for multiwinner would turn out to be "you can't
>     have either LNHelp or LNHarm, and both Droop proportionality and
>     monotonicity"...)
>
>     ----
>     Election-Methods mailing list - see http://electorama.com/em for
>     list info
>
>
>
>
> ----
> Election-Methods mailing list - see http://electorama.com/em for list info


-- 
Richard Lung.
http://www.voting.ukscientists.com
Democracy Science series 3 free e-books in pdf:
https://plus.google.com/106191200795605365085
E-books in epub format:
https://www.smashwords.com/profile/view/democracyscience



---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20180204/201e4e65/attachment.html>