[EM] Condorcet Criterion for plurality.

[David Catchpole]

Votes:

A>B>C
A>B>C
A>B>C
B>A>C
B>A>C
C>A>B
C>A>B
C>A>B
C>A>B

Using plurality, C wins. If we assume that voters have rankings, _whether
or not they can express them on their ballots_, then plurality fails a
Condorcet criterion.


On Mon, 11 Dec 2000, Martin Harper wrote:

> Markus Schulze wrote:
>
> > Plurality can be defined (and usually is defined in the academic
> > literature) on preferential ballots. You claim that as plurality
> > depends on LESS than the complete preferences of the voters
> > plurality cannot be defined on preferential ballots. But when
> > you re-think your argument then you will observe that only when
> > plurality depended on MORE than the complete preferences of the
> > voters plurality couldn't be defined on preferential ballots.
>
> Hmm - this feels wrong, but it's hard to put into words why... It just
> seems to me that an integral part of a voting method is the type of
> ballot - 'plurality-on-preferential' is different to plurality.
> Similarly, changing the wording on the ballot significantly would also
> indicate a slightly different voting method: there's a difference between
> asking the voters to 'put in order until you don't care or don't know',
> and asking them to 'put in order all those who you support'.
>
> So 'plurality-on-preferential' fails condorcet - but how do you determine
> if 'plurality' fails condorcet? Do you first prove that
> 'plurality-on-preferential' and 'plurality' are the 'same' method? And,
> more importantly, how do you determine if Approval Voting passes the
> criterion?
>
>

-------------------------------------------------------------------------------
Guy at hot dog stand:	Yo, Dalai Lama, what'll you have?
The Big DL:		Make me one with everything.
				-Thanks to www.newgrounds.com