[EM] [CES #4429] Looking at Condorcet

[Raph Frank]

On Thu, Feb 2, 2012 at 3:22 AM, Dave Ketchum <davek at clarityconnect.com> wrote:
> Voter can vote as in:
> .     FPTP, ranking the single candidate liked best, and treating all others
> as equally liked less or disliked.
> .     Approval, ranking those equally liked best, and treating all others as
> equally liked less or disliked.
> .     IRV, giving each voted for a different rank, with higher ranks for
> those liked best, and realizing that IRV vote counters would read only as
> many of the higher rankings as needed to make their decisions.
> .     Condorcet, ranking the one or more liked, using higher ranks for those
> liked best, and ranking equally when more than one are liked equally.

You can combine all of those methods (though not IRV) into a
super-ballot.  I think this was suggested on this list at some point.

Basically, you give each candidate a rating, but fractional rankings
are allowed.

You then construct the condorcet matrix.  If a voter ranks A as 1 and
B as 1.5, then that counts as half a vote for A over B.

However, if the voter votes A as 1 and B as 5, then that only counts
as 1 vote for A over B, since each voter gets a maximum of 1 vote.

Ranked candidates are considered preferred by a full vote over unranked.

This allows the voters to decide which method to use.

Condorcet
- just rank the candidates in order of your choice, equals allowed

Approval
- rank approved candidates as 1

Range/Scorevoting
- rank all candidates from 0 to 1 (0 = favorite)

Each voter could decide, without one group having much more power than others.

Abstains aren't handled that well.  Scorevoting assumes that they
should have no effect.

In theory, the rule could be that if a candidate is not ranked, then
no preference ordering is assumed.  The ballot would have a zero for
all comparisons relative to that candidate.

However, that is a lot of hassle, maybe there could be a box to
indicate how you want unranked candidates handled.  Do you want them
equal lowest rank, or abstain.