Consensus, Condorcet(0), and Condorcet(1/2)

Steve Eppley seppley at alumni.caltech.edu
Sun Jul 28 08:53:55 PDT 1996

```Hugh T wrote:
>Steve E wrote:
>>Which of the following is the greater violation of democratic
>>principle in a 2-candidate race:
>>  1. Electing candidate A even though A lost to B (46 to 54).
>>  2. Electing candidate A even though A lost to B (34 to 46,
>>       with 20 who have no preference between them).
-snip-

>But in the tiebreak we are comparing the results of at least three
>pairwise races.
-snip-

Sure, I know that.  But there's an important connection.  What is
the "largest votes against" tie-break measuring?  What's the meaning
of each pairwise race?

The C>A=B voter is already counted as a vote against A in the AC
pairing and as a vote against B in the BC pairing.  You seem to
be saying that this voter should also be counted in the AB pairing
because s/he'd benefit if we do that.  I don't think that's a
sufficient reason, and I think it would muck up the meaning of
what's being measured.

The question I posed (see above) tries to explore that meaning.
If you didn't look at it because it's about 2-choice elections,
then I hope you'll take a look at it now.

* *

>From an older message:

>Consider a slight modification of this scenario: Dole's strategists
>get a minority of his supporters, 18 per cent of the total, to
>order-reverse (alternatively, they really prefer Nader), the rest
>sincerely vote Dole, Clinton.
>
>28 Dole, Clinton
>20 Clinton

With Condorcet(0) the Dole reversers would be burned at the stake if
scenario in my opinion.

The alternative--that 18 D>N>C voters really do prefer Nader--is more
plausible.  A question we shouldn't ignore about the alternative
scenario is: who *ought* to win with those sincere preferences?
Why not Nader?  If the win is instead accorded to Clinton, 48 voters
will be happier and 52 will be unhappier.  If the win is accorded to
Dole, 46 voters will be happier and 54 will be unhappier.

---Steve     (Steve Eppley    seppley at alumni.caltech.edu)

```