Abd ul-Rahman Lomax wrote:
At 11:57 PM 4/24/2010, Kevin Venzke wrote:
Hi Abd,
--- En date de : Sam 24.4.10, Abd ul-Rahman Lomax
<[email protected]> a écrit :
> This is what is common with the
> use of voting systems criteria to study methods. Scenarios
> are created, sometimes cleverly, to cause a failure of a
> criterion. Does it matter if those conditions never exist?
> It should.
For the simple question of whether the criterion is satisfied or failed,
no it doesn't. Of course people then do go on to disagree about whether
certain criteria are important, and why. There is nobody who thinks every
single criterion is important.
That's right. But until utility analysis started to be done, the
arguments had practically no foundation, they were just ideas about what
democracy should look like, sometimes intuitions, and sometimes quite
deceptive. Some criteria may be positively harmful, and Later No Harm is
one of those. No method that maximizes utility can satisfy Later No
Harm, no method that finds the best compromise winner can satisfy it.
And no method that maximizes social utility, overall satisfaction, can
satisfy the majority or condorcet criteria, as fundamental as they seem,
when only a single ballot is used. They can by using a second ballot to
ratify (or reverse) an original election that finds the utility maximizer.
To me it seems that wouldn't be the case either. Consider the case of a
top-two runoff (with Range as the first round) where the two winners are
both supported by a minority. Then no matter who wins the runoff, the
method as a whole has failed the Majority (and Condorcet) criterion.
Unlikely? Perhaps, but one failure is enough. Of course, you could then
argue on basis of social utility (as you have), but you can't say the
method passes the criteria.
One could also formulate criteria based on score, for instance: "if a
candidate X is given more than half the points given by voters in that
election in total, he should win" - a score/Range version of Majority.
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