Markus said:
In the voting recommendation to the DEBIAN project, you can find a very interesting comment to this question. Norman Petry wrote (6 Feb 2001):
Regardless of what names we use when referring to these methods during our committee discussions, I think it is appropriate that if one of these variants is recommended to Debian that it be named SCHULZE'S METHOD. This is because:
1. Schulze, version 1: The 'Beat-Or-Tie-path' method was first proposed by
Markus Schulze on Sat, 4 Oct 1997 (see EM Archives, "Re: Condorect sub-cycle
rule"). Unfortunately, eGroups has not archived this message, but it can be
found at Rob's site, in this text file (but mistakenly referred to there as
"Tideman's Method"): http://www.eskimo.com/~robla/em/archive/em.97q4
Norm, in that message, points out that "Schulze's method" uses beat-or-tie-paths rather than beatpaths. There's been some vagueness about which of those you refer to as "Schulze's method".
2. Schulze, version 2: The 'Schwartz Sequential Dropping' (SSD) method was first proposed by Markus Schulze on Mon, 10 Aug 1998. His description can be found here: http://groups.yahoo.com/group/election-methods-list/message/673
In that proposal, it isn't clear what you mean by "potential wininers". You don't define the term there. I suppose that if something is defined slopily or vaguely enough, that leaves much latitude for saying what it is.
No one can prove what you meant in that proposal.
In any case, I didn't mean to imply that I consider it important who first proposed SSD, or whether your proposal in '98 was SSD, CSSD, or neither.
Markus' version of 'Cloneproof SSD' uses a slightly different (and imo better) tiebreaker than Mike's version, but the two methods are otherwise identical.
You'd suggested comparing margins when 2 opposing beatpaths (or beat-&-tie-paths?) are equal because their weakest defeat is equal. I hadn't bothered to add that, because I'm mostly interested in public elections, and because even in committees, equal opposing beatpaths won't be common. Of course there's nothing wrong with adding that provision.
There were aspects of your tie solution that you later retracted when you discovered that they had undesirable properties.
Markus said:
Another interesting question is: In so far as you considered neither independence of clones nor reversal symmetry to be important, why did you propose an election method that is more complicated than Schwartz//MinMax(VotesAgainst)?
I reply:
I don't know what you mean by MinMax. MinMax has been used with so many meanings that it's quite useless as a method name. Perhaps you're using MinMax to refer to PC.
I agree that I don't consider reversal symmetry important. As for clone independence, it's desirable, but far from essential. But what I was saying in my recent message was that the clone independence _of a tiebreaker_ isn't important, because no one is going to have a strategy dilemma about what to do in order to take advantage of a tie. Ties of all kinds are vanishingly rare in public elections (unless Copeland is used). Even in committees, ties aren't common, and clone-independence of a tie solution isn't really important.
So far as I'm aware, SSD is clone-independent in public elections (where there are no pairwise ties), but not in coimmitees with few voters (where there might be pairwise ties).
MAM (Maximize Affirmed Majorities), also called Ranked-Pairs, is clone-independent in public elections and in committees.
Though clonen-independence is desirable, that isn't the main advantage, for me, that SSD and MAM have over PC. The more important advantages, for me, are:
1. PC fails Condorcet Loser, Majority Loser, and Mutual Majorilty (in descending order of likely importance in campaigns). Those criterion failures are important only because they could be used against a PC proposal. When those criteria are defined so as to meaningfully apply to all methods, Plurality fails them too, which of course greatly reduces their importance in campaigns to replace Plurality with PC. Still, possible criticism of PC in campaigns, by academics and IRV advocates is probably PC's main disadvantage with respect to SSD and MAM.
2. SSD and MAM have been shown to meet GSFC and SDSC. PC hasn't been shown to meet those criteria. If anyone can show that PC passes or fails those critreria, they're invited to do so.
I consider SFC and GSFC to be the biggest, and most exclusive advantages of Condorcet wv. The fact that SSD and MAM have been shown to meet GSFC greately increases their value.
GSFC is the deluxe SFC that applies even when there's no CW.
PC has been shown to meet SFC.
Mike Ossipoff
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