[EM] Using Schulze Election Method to elect a flexible amount of winners

robert bristow-johnson rbj at audioimagination.com
Tue Oct 4 21:39:43 PDT 2016

it seems to me that *any* Condorcet-compliant method (Schulze, MinMax, Ranked-Pairs) can be extended from single-winner to multi-winner.
why not just run the procedure multiple times, each time removing from the list the candidate that was elected from the single-winner
procedure and, at the same time, reducing the number of office seats available by one?  why can't we do that?  what is wrong with that?
seems to me that it would work.
r b-j

---------------------------- Original Message ----------------------------

Subject: Re: [EM] Using Schulze Election Method to elect a flexible amount of winners

From: "VoteFair" <ElectionMethods at VoteFair.org>

Date: Tue, October 4, 2016 8:23 pm

To: "election-methods at lists.electorama.com" <election-methods at lists.electorama.com>


> On 10/3/2016 7:29 AM, Paul Smits wrote:

> > Now the question arose how we could use the Schulze method in a decision

> > where the amount of winners is also up for debate. ...


> Single-winner methods, such as the Condorcet-Schulze method and the

> Condorcet-Kemeny method, cannot be used to elect a second winner. Why?


> The voters who favor the most popular choice need to have their

> influence reduced in order to correctly identify the second winner.


> As explained here,


> http://www.votefair.org/calculation_details_representation.html


> "Without this adjustment the same voters who are well-represented by the

> most popular choice could also determine the second-place winner."


> To understand this concept, imagine a group of participants who vote in

> order to choose two events that will happen at the same time. The

> single-winner method can easily identify the most popular activity. But

> if the single-winner method is also used to identify the "second-most

> popular" activity, then the second activity will not be well-attended

> because most of the participants will attend the most popular activity.

> In the meantime, the remaining participants, who were outvoted, will

> not be interested in the second activity, and they will be frustrated

> that their preferred activity was not chosen as the second event.


> I created VoteFair representation ranking to handle such situations.

> Later, Markus Schulze created what he calls Schulze-STV to serve this

> purpose.


> The link above explains how VoteFair representation ranking works. My

> ebook "Ending The Hidden Unfairness In U.S. Elections" (which also

> applies to other nations as explained near the end of the book) also

> explains this concept. It is available for most ebook readers, and I

> priced it as low as allowed (which mostly just covers the download fee).


> BTW, what many people overlook is the fact that "second-most popular"

> has multiple possible interpretations.


> If you have more questions, please ask. And thank you for learning

> about election-method reform!


> Richard Fobes



> On 10/3/2016 7:29 AM, Paul Smits wrote:

>> Dear election enthusiasts,


>> First of all I would like to congratulate you on the great wealth of

>> works and ideas you brought into the world of voting/election methods.

>> Even though it may be out of the scope of your focus, I have a

>> consideration I would like to consult you on. If I came to the wrong

>> place, let me know.


>> In my organisation we are implementing the Schulze method to all

>> situations where a single winner or sorted list of winners has to be

>> chosen from more than two options. We basically did a straight

>> implementation from the wikipedia pseudocode into our own online voting

>> system.


>> Now the question arose how we could use the Schulze method in a decision

>> where the amount of winners is also up for debate. We used to make this

>> decision by conducting an approval vote with a certain threshold for

>> winners. I was not happy about this slightly arbitrary choice of

>> threshold. Now some colleagues wish to again see some value by which the

>> quantity of support for all the candidates can be understood.


>> I propose to use the Schulze method and add an option of "no further

>> winner" to the list of candidates, which is comparable to what is

>> defined as the "status quo" as mr Schulze described in his paper in the

>> section super-majorities. I.e. the status quo is 'no winners', and each

>> candidate has to beat the option of 'no winners' in order to qualify.


>> Would you think this is an adequate procedure to make this decision on

>> both the choice of winners and the amount of winners? I am aware there

>> is a risk of electing no candidates, or all candidates. But at least it

>> is less artificial than a fixed percentage of votes as was done before.


>> Best regards,


>> Paul L. Smits




>> ----

>> Election-Methods mailing list - see http://electorama.com/em for list info


> ----

> Election-Methods mailing list - see http://electorama.com/em for list info



r b-j                  rbj at audioimagination.com

"Imagination is more important than knowledge."
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