[EM] Proportional multi-winner ranked voting methods - guidelines?

Tue Feb 21 16:24:54 PST 2017

On 2/20/2017 11:57 PM, Armando wrote:
 > ...
 > I am looking for multi-winner election with fair proportional
 > representation.
 > ...
 > I would very appreciate if you can help me giving “guidelines”,
 > explaining pros and cons, advising further readings. ...

I suggest that you look at VoteFair ranking, which is a method I 
developed years ago, over a span of about a decade.

It is described in detail in my book "Ending The Hidden Unfairness In 
U.S. Elections," which is available through multiple e-book reading 
platforms.  The book includes lots of illustrations to make the concepts 
easier for "average" (non-math) readers to understand.  (With so many 
illustrations the file size is large and the low price basically just 
covers the download fee.)

Near the end of the book I explain that the same system would work in 
other nations simply by increasing the number of parliament members who 
are elected using cross-district voting methods.

Based on your questions, here is what I think is the most important 
concept for you to understand:

STV (the Single Transferable Vote) and similar methods(!) are designed 
for a small number of available seats, and it is a mistake to think that 
such a method can simply be used repeatedly to achieve fair results for 
a large number of available parliament seats.

You seem to correctly understand that ranking candidates -- rather than 
using single-mark ballots -- is essential for fair results.  PR 
(proportional representation) methods in Europe did not get this part of 
PR correct.  That's why it is easy for campaign contributions (money) to 
easily control European politics.

With these concepts in mind, I suggest that you read the overview of 
VoteFair ranking, which is here:

http://www.votefair.org/calculation_details.html

Or, for your convenience, here is a copy of those words, but without the 
links:

........ begin quote ..........

VoteFair ranking is a calculation method that includes the following 
components:

* VoteFair popularity ranking, which identifies the most popular choice, 
the second-most popular choice, the third-most popular choice, and so on 
down to the least popular choice.  Here is a link to details about 
VoteFair popularity ranking.

* VoteFair representation ranking, which identifies the 
most-representative choice (which is the same as the most popular choice 
according to VoteFair popularity ranking), the second-most 
representative choice, and additional representation levels.  The 
second-most representative choice is identified after appropriately 
reducing the influence of the voters who are well represented by the 
most-popular (and most-representative) choice.  Without this adjustment 
the same voters who are well-represented by the most popular choice 
could also determine the second-place winner.  Here is a link to details 
about VoteFair representation ranking.

* VoteFair party ranking, which identifies the most-popular political 
party (which is the same as the most popular choice according to 
VoteFair popularity ranking), the second-most popular political party 
(which is the same as the second-most representative choice), and the 
political party that deserves to be recognized as the third-most popular 
political party.  The third-most popular party is identified after 
appropriately reducing the influence of the voters who are well 
represented by the first-ranked and second-ranked political parties. 
Without this adjustment the same voters who are well-represented by one 
of the most popular parties could create a "shadow" party that occupies 
the third position, which would block smaller parties from that third 
position.  Here is a link to details about VoteFair party ranking.

* VoteFair partial-proportional ranking, which identifies candidates who 
failed to win a legislative seat in their district, yet deserve to win 
special legislative seats for the purpose of compensating for unfair 
district boundaries, making it possible to elect legislators from 
"third" political parties (especially when the main political parties 
fail to fully represent their political priorities.  Without this 
adjustment the balance of power among political parties in the 
legislature can easily fail to match the voters' preferences for 
political parties.  Here is a link to details about VoteFair 
partial-proportional ranking.

........ end quote ..........

For details about any part of VoteFair ranking, please go to the webpage 
and click the appropriate link.

Thanks for your interest in learning how voting should be done!

If you have questions, just ask.

Richard Fobes
Author of "The Creative Problem Solver's Toolbox" which has been 
published around the world in 10 languages

On 2/20/2017 11:57 PM, Armando wrote:
> Hello,
> I am a new subscriber, and I am not an expert.
>
> I am looking for multi-winner election with fair proportional
> representation.
> I would like to find a method allowing voters to vote “transversally”
> through parties: it could decrease conflicts.
> I would very appreciate if you can help me giving “guidelines”,
> explaining pros and cons, advising further readings. I thank you very
> much in advance.
>
> I would like to open two issue:
>
> *1. Best multi-winner ranked method for a PROPORTIONAL ASSEMBLY*
>
> I read of CIVS
> <http://civs.cs.cornell.edu/proportional.html> and Schulze-STV
> <https://en.wikipedia.org/wiki/Schulze_STV>, and I thought they where
> the best for my case.
> They seems better then “traditional” STV since they satisfy more
> criteria, with less strategic vote risk.
> However I don’t understand differences among various condorcet’s
> multi-winner systems.
>
> I knew also De Borda-based multiwinner systems:
> _http://www.deborda.org/faq/_
> It seems De Borda got popular in the spanish party of Podemos recently:
> but they used a non-proportional De Borda to elect their national
> assembly (with DesBorda
> <https://vistalegre2.podemos.info/la-asamblea/#Sistema_de_votacion> by
> Echenique).
> Others in the same party proposed (failing) the Dowdall variant
> <https://forms.podemos.info/wp-content/uploads/gravity_forms/247-6edda8669dd26a992ea894158e3e3d91/2016/12/PropuestaPodemosEnMovimiento.pdf>
> of De Borda (it is used in Nauru’s elections too). It seems it would
> have been more proportional (here a simulation
> <http://www.eldiario.es/politica/datos-cocina-votaciones-Podemos_0_612089572.html?utm_content=buffer93f9f&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer>,
> 3rd figure, compare /Sistema utilizado (/DesBorda) with /Propuesta de
> Anticapitalista/ (Dowdall-Borda)).
>
> However De Borda Institute recommends Quota Borda
> System http://www.deborda.org/faq/voting-systems/what-is-the-quota-borda-system-qbs.html
>
> Actually I think there are few differences, for voters, between a
> condorcet and a borda ballot (always numbering candidates). Is it?
> But what are the difference in /results, /considering the proportional
> variants?
>
> Do you think PR-open list system helps more the more “conflictual”
> candidates (as could be the leader of each party, since they are
> overexposed to party electors “love” and to opposers “hate”)?
>
> *2*. *Best multi-winner ranked method for a PROPORTIONAL MIXED-PARTIES
> GOVERNMENT*
> I was fascinated by De Borda Institute’s idea: a system to elect
> directly a mixed government, where voters choose candidates AND best
> offices for them.
> They call it Matrix
> Vote http://www.deborda.org/faq/voting-systems/what-is-the-matrix-vote.html
>
> Could be possible to reach this purpose also with other systems, for
> example Schulze-stv?
>
>
> Best regards,
> Thank you in advance
>
> Armando Pitocco
>
>
>
>
>
> ----
> Election-Methods mailing list - see http://electorama.com/em for list info
>