Re: Multi-winner Condorcet, vs STV

Hallo,

in my opinion, the Schulze STV method is
the best multi-winner election method:

http://en.wikipedia.org/wiki/Schulze_STV

See also this list of papers:

http://m-schulze.webhop.net/schulze1.pdf
http://m-schulze.webhop.net/schulze2.pdf
http://m-schulze.webhop.net/schulze3.zip

The Schulze STV method is a method of
proportional representation by the single
transferable vote that doesn't compromise
any of the properties that are satisfied
by the Schulze single-winner election method
("cloneproof Schwartz sequential dropping").

Furthermore, the Schulze STV method minimizes
the vulnerability to free riding and vote
management strategies.

The Schulze STV method is very complicated
because I try to create a multi-winner election
method that minimizes all known strategic
problems simultaneously.

Markus Schulze

On Fri, Dec 11, 2009 at 10:53:19PM +0100, Markus Schulze wrote:
> Hallo,
>
> in my opinion, the Schulze STV method is
> the best multi-winner election method:
>
> http://en.wikipedia.org/wiki/Schulze_STV
>
> See also this list of papers:
>
> http://m-schulze.webhop.net/schulze1.pdf
> http://m-schulze.webhop.net/schulze2.pdf
> http://m-schulze.webhop.net/schulze3.zip
>

And is the method already adopted by Debian, IIRC.

All best,

AndyC

On Fri, Dec 11, 2009 at 10:27:48PM +0000, Andrew M.A. Cater wrote:
> On Fri, Dec 11, 2009 at 10:53:19PM +0100, Markus Schulze wrote:
> > Hallo,
> >
> > in my opinion, the Schulze STV method is
> > the best multi-winner election method:
> >
> > http://en.wikipedia.org/wiki/Schulze_STV
> >
> > See also this list of papers:
> >
> > http://m-schulze.webhop.net/schulze1.pdf
> > http://m-schulze.webhop.net/schulze2.pdf
> > http://m-schulze.webhop.net/schulze3.zip
> >
>
> And is the method already adopted by Debian, IIRC.

Debian does not do multi-winner elections/votes.

But of course one can always frame a multi-winner election as a single-qwinner
on$e: For example with 2 seats and 4 candidates A,B,C and D, provide 6 options.
A&B,A&C,A&D,B&C,B&D,C&D.

Cheers,
Bill.

Markus Schulze writes ("Re: Multi-winner Condorcet, vs STV"):
> in my opinion, the Schulze STV method is
> the best multi-winner election method:

Thanks for pointing us to that. Interesting reading.

I wouldn't support such a thing for a public governmental election,
because of the need for computer involvement. Public elections should
be done with simple and readily verifiable processes - ie, pencil and
paper.

However I like the approach and I think it would work well for SPI.
It would certainly be better than the current system. I would be
happy to see Schulze STV adopted for SPI board elections.

> The Schulze STV method is very complicated because I try to create a
> multi-winner election method that minimizes all known strategic
> problems simultaneously.

Quite.

Is there any software which implements this method already ? I would
be happy to write some. Is there a standard format for STV preference
ballot input data ?

Ian.

Ian Jackson wrote:
> Markus Schulze writes ("Re: Multi-winner Condorcet, vs STV"):
> > in my opinion, the Schulze STV method is
> > the best multi-winner election method:
>
> Thanks for pointing us to that. Interesting reading.
>
> I wouldn't support such a thing for a public governmental election,
> because of the need for computer involvement. Public elections should
> be done with simple and readily verifiable processes - ie, pencil and
> paper.

This is nonsense. As far as I can tell, in the method Markus proposes
ballots can be cast with just pencil and paper -- which is the important
part on which pencil and paper should be used. The result counting part
is going to involve computers *anyway*, but since the input data (filled
ballots) is available and verifiable, this is not a problem because
different parties can have their own software.

--
Alvaro Herrera Vendo parcela en Valdivia:
http://valdivia.vivastreet.cl/loteos-lotes+valdivia/parcela-en-cabo-blanco--valdivia/19288372
"Si quieres ser creativo, aprende el arte de perder el tiempo"

On Mon, Dec 14, 2009 at 11:51:54AM -0300, Alvaro Herrera wrote:
> Ian Jackson wrote:
> > I wouldn't support such a thing for a public governmental election,
> > because of the need for computer involvement. Public elections should
> > be done with simple and readily verifiable processes - ie, pencil and
> > paper.
>
> This is nonsense. As far as I can tell, in the method Markus proposes
> ballots can be cast with just pencil and paper -- which is the important
> part on which pencil and paper should be used. The result counting part
> is going to involve computers *anyway*, but since the input data (filled
> ballots) is available and verifiable, this is not a problem because
> different parties can have their own software.

Just to prevent this thread from ballooning really hugely in size with
off-topic comments, I suggest that discussion of voting systems for public
governmental elections be held via private email or some more appropriate list,
except insofar as SPI might be involved in any particular governmental
elections (e.g. Open Voting Foundation). Regarding the use of Schulze STV for
SPI elections, interesting idea indeed and the Secretary may wish to consider
it.

- Jimmy Kaplowitz
jimmy(at)spi-inc(dot)org

(I have changed the subject line because this thread is no longer
about the SPI elections, but about voting in general.)

Alvaro Herrera writes ("Re: Multi-winner Condorcet, vs STV"):
> Ian Jackson wrote:
> > I wouldn't support such a thing for a public governmental election,
> > because of the need for computer involvement. Public elections should
> > be done with simple and readily verifiable processes - ie, pencil and
> > paper.
>
> This is nonsense. As far as I can tell, in the method Markus proposes
> ballots can be cast with just pencil and paper -- which is the important
> part on which pencil and paper should be used. The result counting part
> is going to involve computers *anyway*, but since the input data (filled
> ballots) is available and verifiable, this is not a problem because
> different parties can have their own software.

Perhaps you do things differently. Conventional STV can be
implemented entirely with pencil and paper, using the physical
ballots. It's a bit more complicated than first-past-the-post (aka
simple plurality) but the same principles apply.

You sort the ballots into piles according to the first preference.
You count each pile. Decide which candidate is eliminated. Take
their pile and split it into sub-piles according to 2nd preferences.
Repeat. The number of piles can get fairly high, but not unmanageable
for an ordinary civic hall or whatever.

Why is it important do have a system can be done without computers ?
Because having the input ballots verifiable and the counting process
checkable (eg by statistical methods) is not sufficient. You also
need a fallback method for if the verification process shows problems.

If I can demonstrate (to a court, say) that the computers are
malfunctioning, I need to be able to tell the court or the electoral
commission or whatever:

This meets the criterion in section <whatever> of the election law,
which says that there is significant doubt [or whatever the phrasing
should be]. Thus you must order a manual recount as provided in the
law.

The requirement is that the law governing the election must provide a
workable and occasionally-tested process which can be used to
authoritatively determine the result. That method must be very
resistant to manipulation and must use only processes that a court can
supervise directly.

Courts can't supervise software. They can in theory evaluate
competing claims about software's behaviour (although in practice
courts are far too ignorant, and anyway definitively determining the
behaviour of software is fraught with difficulty as we programmers
know). But that's not sufficient, because we must not be left in the
situation where we depend on software for the answer to the election
but there is no software which can be demonstrated to be sound. If
that were to happen then the election would either have to be
cancelled pending a rewrite of the rules (or worse, the software), or
allowed to be stolen.

It's OK for such a manual recount process to be slow, but it needs to
be feasible. It is for conventional STV but not for Shultze STV.

Ian.

Jimmy Kaplowitz writes ("Re: Multi-winner Condorcet, vs STV"):
> Regarding the use of Schulze STV for SPI elections, interesting
> idea indeed and the Secretary may wish to consider it.

Ideally the membership would make this decision as a change to the
bylaws but our constitutional situation is still a bit poor. Even so
I think the election method should be decided by the Board rather than
the Secretary.

So here are two draft resolutions:

2009-12-14.iwj.1sch

Whereas:

1. Multi-winner Condorcet as previously used by SPI for elections to
the Board can be unfair due to lack of proportionality.

2. Schultze STV is felt to be the currently best available method
for elections to elect multiple candidates.

3. These factors outweigh the complexity and newness of Schultze STV.

The Board resolves that:

4. Schultze STV will be used as the voting and counting method for
Board elections in the future.

5. The version of Schultze STV to be used is that defined by
Markus Schulze:
_Free Riding and Vote Management under Proportional
Representation by the Single Transferrable vote_
(draft, 28 March 2008)
section 5
http://m-schulze.webhop.net/schulze2.pdf
of which the Secretary is asked to take a copy and maintain
on the SPI website.

6. If clarifications and/or amendments are necessary, the Secretary
will consult with Markus Schulze (if Markus is willing) and the
membership. Such clarifications and amendments should be reported
to the Board for approval at a Board Meeting well prior to the
election at which they will enter into force.

If you prefer plain STV:

2009-12-14.iwj.1stv

Whereas:

1. Multi-winner Condorcet as previously used by SPI for elections to
the Board can be unfair due to lack of proportionality.

2. Conventional STV is an adequate method for our needs, and is
simple, well-defined and well-established.

3. These factors outweigh the deficiencies which might be remedied by
a more complex or newer system.

The Board resolves that:

4. Conventional STV (Single Transferrable Vote) will be used as the
voting and counting method for Board elections in the future.

5. The version of STV to be used is that defined and recommended
by the UK Electoral Reform Society. Currently this may be
found in the booklet
Robert A Newland, Frank S Britton:
_How to conduct an election by the Single Transferable Vote_
http://www.electoral-reform.org.uk/oldsite20070123/votingsystems/stvrules.htm
of which the Secretary is asked to take a copy and maintain
on the SPI website. The instructions regarding the physical
management of the election are to be disregarded; the reference is
only authoritive as to ballot form and counting algorithm.

6. If clarifications and/or amendments are necessary, the Secretary
will consult with the membership. Such clarifications and
amendments should be reported to the Board for approval at a Board
Meeting well prior to the election at which they will enter into
force.

Ian.