[EM] An interesting real election

Andrew Myers andru at cs.cornell.edu
Sun Jan 30 21:08:44 PST 2011


It's a little tough to spot without the coloring that CIVS does, but #1 
loses pairwise to #6. This makes #2 win according to Schulze. As Markus 
points out, #2 is the candidate with the weakest pairwise defeat (13-9 
vs the 14-13 defeat of #1 by #6).

-- Andrew

On 1/30/11 2:33 PM, Paul Kislanko wrote:
> How is #1 not a Condorcet Winner, since #1 pairwise-beats every other 
> alternative?
>
> ------------------------------------------------------------------------
> *From:* election-methods-bounces at lists.electorama.com 
> [mailto:election-methods-bounces at lists.electorama.com] *On Behalf Of 
> *Andrew Myers
> *Sent:* Saturday, January 29, 2011 4:41 PM
> *To:* Election Methods Mailing List
> *Subject:* [EM] An interesting real election
>
> Here is an unusual case from a real poll run recently by a group using 
> CIVS. Usually there is a Condorcet winner, but not this time. Who 
> should win?
>
> Ranked pairs says #1, and ranks the six choices as shown. It only has 
> to reverse one preference. Schulze says #2, because it beats #6 by 
> 15-11, and #6 beats #1 by 14-13. So #2 has a 14-13 beatpath vs. #1. 
> Hill's method ("Condorcet-IRV") picks #6 as the winner.
>
> -- Andrew
>
> 		1. 	2. 	3. 	4. 	5. 	6.
> 1.
> 		- 	13 	15 	17 	16 	13
> 2.
> 		9 	- 	13 	14 	17 	15
> 3. 		11 	11 	- 	13 	15 	14
> 4.
> 		9 	10 	10 	- 	14 	13
> 5.
> 		11 	10 	9 	10 	- 	13
> 6.
> 		14 	11 	11 	13 	10 	-
>
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