[EM] Bad Condorcet winners?

[Tom Ruen]

> Votes             Candidate (rating)
> -----     ---------------------------------
>  49%       A(10)                 B(1)  C(0)
>   3%       B(10)  A(9)                 C(0)
>  48%       C(10)                 B(1)  A(0)

This shows an example where Condorcet demands more care from voters in lower
rankings.
Voters for A and C should simply bullet vote if they hate the centrist.
They can also consider between the centrist and the opposite party which
they prefer if their candidate can't win.
Many voters might choose the opposite party if they were being thoughtful.

In Condorcet, this should be: A=49, C=48, BA=3.
Then A is Condorcet candidate.

If they're really worried about B: AC=49, CA=48, BA=3.
This more powerfully resists the centrist.


Tom

----- Original Message -----
From: "Bart Ingles" <bartman at netgate.net>
To: <election-methods-list at eskimo.com>
Sent: Thursday, March 15, 2001 1:27 AM
Subject: Re: [EM] Bad Condorcet winners?


>
> Tom Ruen wrote:
> >
> > I've also met a number of people, who when I talked about IRV, they were
> > deathly afraid it would have allowed Nader to win the presidency. IRV
never
> > helps a weak middle win, but Condorcet will. It actually took me a while
to
> > convince my cousin that he actually preferred Bush to Nader second. He
> > assumed he would somehow be forced to vote Nader second.
> >
> > Well, this shows that in a Condorcet election voters must take lower
> > preferences more seriously than in IRV.
>
>
> Here's my basic "bad Condorcet" example (actually a low-utility
> Condorcet example).  It doesn't seem particularly implausible to me, but
> requires that utility include a non-policy component.  For example, the
> middle candidate could be a centrist but unpopular for other reasons.
>
> In the following example, voter ratings are used to show an
> approximation of utility.  Candidates A, B, and C are voter-rated on a
> scale of from 0-10, with 10 being the voter's favorite, and 0 the least
> favorite:
>
> Votes             Candidate (rating)
> -----     ---------------------------------
>  49%       A(10)                 B(1)  C(0)
>   3%       B(10)  A(9)                 C(0)
>  48%       C(10)                 B(1)  A(0)
>
> Without trying to make too much of the average or aggregate voter
> ratings, it seems obvious that 97% of the voters despise candidate B,
> even though B is the Condorcet winner.
>
> Bart