[EM] proposal: weighted pairwise comparison

[bql at bolson.org]

On Wed, 9 Jun 2004 Dgamble997 at aol.com wrote:

> You wrote:
>
>> Tally:
>> 1. Pairwise tally, using the ranked ballots only. Elect the Condorcet
>> winner if one exists.
>
>
> So in the examples:
>
> 45 A 100 > B 70 > C 0
> 10 B 100 > A 70 > C 0
> 5  B 100 > C 70> A 0
> 40 C 100 > B 70 > A 0
>
>
> 45 A 100 > B 10 > C 0
> 10 B 100 > A 90 > C 0
> 5  B 100 > C 90 > A 0
> 40 C 100 > B 10 > A 0
>
> B wins in both cases even though in the second example B is disliked by 85%
> of voters.

Yup. Both are decided by plain Condorcet, which only considers rankings 
not ratings, and B wins. Of the methods on my Election Calculator, only 
IRV selects A. B is the compromise candidate. Everyone is happy enough 
with B.

See the first examle:

http://bolson.org:8080/v/et?vrr=-r&if=-d&cand=3&data=*45+10%2C7%2C0%0D%0A*10+7%2C10%2C0%0D%0A*5+0%2C10%2C7%0D%0A*40+0%2C7%2C10

In your second example, B being devalued and B-voters throwing in more 
with A, IRNR picks this up and selects A (rank-only methods other than IRV 
still choose B):

http://bolson.org:8080/v/et?vrr=-r&if=-d&cand=3&data=*45+10%2C1%2C0%0D%0A*10+9%2C10%2C0%0D%0A*5+0%2C10%2C9%0D%0A*40+0%2C1%2C10


Brian Olson
http://bolson.org/