[EM] Spoiler Effect on Wikipedia

Markus Schulze markus.schulze at alumni.tu-berlin.de
Fri Nov 12 17:22:54 PST 2004

Dear Eric,

you wrote (12 Nov 2004):
> I would suggest the one proposed by Dr. Tideman which I believe can
> be found here:
> http://condorcet.org/emr/criteria.shtml

I don't see that Blake Cretney uses the resolute model. The resolute model
says that for every possible set of ballots a candidate who is elected with
certainty under this set of ballots is determined in advance.

Blake writes e.g.: "Name: Reversal Symmetry Criterion. Definition: If
alternative X wins (excluding ties), and all rankings on all ballots are
reversed, then X must lose." If he really used the resolute model then the
restriction "excluding ties" was superfluous because in the resolute model
ties are not possible.

I rather have the impression that when Blake says "If an alternative
outside the clone set won for the old ballots, the same alternative
must win for the new ballots" then he means: "For every possible random
number X: If alternative A(X) outside the clone set won for the old
ballots, alternative A(X) must win for the new ballots."

Markus Schulze

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