[EM] Random Ballot fails IIAC

Markus Schulze markus.schulze at alumni.tu-berlin.de
Mon Jan 21 03:06:32 PST 2002

Dear Mike,

you wrote (20 Jan 2002):
> Since IIAC doesn't stipulate sincere voting, or otherwise
> make stipulations about how people vote, and since you confirmed,
> when I asked, that nothing of the sort is assumed, then when
> my example has a voter voting insincerely, that doesn't violate
> the premise of that IIAC criterion. And so, when the addition of
> a candidate increases the probability that a previously-existing
> candidate will win, given the inclusion of such a voter, in my
> example, that is an IIAC failure by Random Ballot.

Whoa, cowboy. I suggest that you should post your "proof" that
Random Ballot violates IIAC to a scientific journal. Your post
would be a revolution for the understanding of Arrow's Theorem  ;-)

You wrote (20 Jan 2002):
> Some define CC in terms of actual votes, with the result that
> Plurality passes, and so, to keep Plurality from passing, they
> say that the criterion, by their definition, applies only to rank
> methods. That greatly reduces the meaningfulness and usefulness
> of CC, and it's a shabby contrivance to avoid an undesired result.

Nope! This doesn't reduce the meaningfulness and usefulness,
since these people simultaneously presume that the voters always
cast all preferences even when the used method (e.g. plurality)
doesn't use all preferences.

Markus Schulze

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