[EM] SSD, RP wrap-up

Markus Schulze schulze at sol.physik.tu-berlin.de
Sun Apr 22 04:30:17 PDT 2001

Dear Mike,

you wrote (18 Apr 2001):
> Markus wrote (18 Apr 2001):
> > Steve Eppley never used the term "BeatpathWinner" in this
> > context. He always used the term "Schulze method." Therefore it
> > seems that you have mixed up the Schulze method and the Beatpath
> > Criterion Method and that some time you began to use these terms
> > synonymously. Please read Steve Eppley's mails in the archive!
> Markus quotes some postings in which Steve calls it Schulze, but
> did I say that Steve never called it that? There was a time when
> he was calling it BeatpathWinner. Steve didn't always call it
> BeatpathWinner. There was a time during which he did.

Nope! Steve Eppley never used the term "BeatpathWinner" in this


You wrote (18 Apr 2001):
> You know, Markus, I wonder if you got "Schulze's method" from
> an article, and then claimed it as your own. I'm not saying you
> did, or that you didn't. But some of the tendencies that you've
> exhibited, like when you were arrogantly claiming that you'd
> introduced us to beatpaths (you later admited that you didn't)
> certainly don't rule that possibility out.

It is certainly an enormous advantage of Ranked Pairs that it
has already been discussed and analyzed in the literature (e.g.:
T. Nicolaus Tideman, "Independence of Clones as a Criterion for
Voting Rules," Social Choice and Welfare, vol. 4, p. 185-206, 1987;
T.M. Zavist, T. Nicolaus Tideman, "Complete Independence of Clones
in the Ranked Pairs Rule," Social Choice and Welfare, vol. 6,
p. 167-173, 1989; Jonathan Levin, Barry Nalebuff, "An Introduction
to Vote-Counting Schemes," Journal of Economic Perspectives, vol. 9,
no. 1, p. 3-26, Winter 1995).

Therefore, if SSD/Schulze/BeatpathWinner had already been mentioned
in the literature then of course I would have said so.


You wrote (19 Apr 2001):
> RP can choose outside the initial Schwartz set. SSD & Cloneproof SSD
> will never do that. Choosing outside the initial Schwartz set isn't
> serious. I'm not aware of it causing a strategy problem, but that
> doesn't mean I'm saying it doesn't. But it's an embarrassment, and,
> as I said before, an aesthetic gaffe. And an avoidable one, since
> we've got excellent methods that don't have that failing.

Could you please post an explicit example where Ranked Pairs
chooses outside the Schwartz set.

Markus Schulze

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