[EM] CR style ballots for Ranked Preferences

[Richard Moore]

Bart Ingles wrote:

> Buddha Buck wrote:
> 
>>Hmm...  I'd love to see an example of this, since I fail to see how it
>>could happen.
>>
> 
> I couldn't find any examples, and wouldn't mind seeing one myself, but
> in addition to Nurmi (who cites Young) here are a couple other mentions
> of the asserted incompatibility between Condorcet criterion and
> consistency:
> 
>    http://www.ucm.es/info/icae/papeles%20seminario/NSPR.pdf
> 
>    http://users.erols.com/aejohns/node4.htm
> (the latter apparently abstracted from Lorrie Faith Cranor's
> dissertation, available at
>    http://lorrie.cranor.org/pubs/voting.html
> 
> 
> 

I didn't have time to look at these closely, but since 
Buddha's proof only applies when all winners (the overall 
winner and the precinct winners) are Condorcet winners, this 
doesn't preclude "All Condorcet-compliant methods are 
inconsistent" from being true. So there is no contradiction, 
but Buddha is right in that the wording he was responding to 
was incorrect. That statement was:

 >> || It may happen that when the electorate is split in 
two arbitrary groups
 >> || and in both groups there is the same Condorcet winner 
(that means, when
 >> || only the voters in the group are considered), this 
alternative might
 >> || fail to be a Condorcet winner for the whole group.

which says nothing about whether the method used is always 
consistent (i.e., consistent regardless of whether CWs exist 
or not).

Richard