[EM] Condorcet 2 - The Sequel ( the same people say the same things)

[Forest Simmons]

Alex said he was willing to agree that IRV might have some advantage over
Condorcet in the one dimensional case, because the "centrist" candidate
might be positioned there opportunistically.

There are many measures of "center" and most of them would lend them
selves to this problem, but the Condorcet center is the "median voter
position" which can be near either extreme of the spectrum if that is
where the majority of the voters are.

Consider the following example:

Voters at positions  1,2,3,97,98,99,100

If the candidates are positioned at 2, 50, 60, and 100,
guess which candidate is closest to the voter median.

In this case the candidate at the extreme of 100 would be the "centrist"
Condorcet candidate, not the midrange candidate at 50 nor the one at 60
closer to the mean.

If another candidate wanted to take advantage of the vacuum near the voter
median of 97, he could position himself there, three units away from the
extreme centrist. The candidate located at 97 would be the Condorcet
winner no matter where the other candidates tried to position themselves.

The candidate at 50 could claim to be "centrist" on the basis of his
midrange position.  The candidate at 60 could claim to be centrist on the
basis of being closest to the mean of the voter positions.

Note that an order preserving transformation like x->x^3 could easily
change which candidate is closest to the mean or midrange, but it will
never change the Condorcet winner if the Condorcet winner is positioned
precisely with the median voter.

This means that our analysis doesn't depend on what units the one
dimensional issue spectrum is measured with, but only on the relative
order.  Any distortion of the issue space by astute politicians would have
to alter the order of the points before it could fool Condorcet.

Forest



On Fri, 8 Aug 2003, Eric Gorr wrote:

> At 9:46 AM -0400 8/8/03, Dgamble997 at aol.com wrote:
> >"IRV succeeds, I believe, in striking a balance between the two
> >somewhat conflicting aims of ensuring that a candidate has majority
> >support ( a candidate does not win with a minority of the vote
> >because the opposition is split) and preventing dominance by
> >candidates/parties who position themselves in the centre."
>
> But, again, the opposition is split and therefore should not win
> because they have a minority of the vote as well.
>
> So, since everyone has a minority, who should win?
>
> The option with the largest minority?
>
> That would seem to be what Plurality does already.
>
>
> --
> == Eric Gorr ========= http://www.ericgorr.net ========= ICQ:9293199 ===
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> == Insults, like violence, are the last refuge of the incompetent... ===
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