[EM] 3 or more choices - Condorcet

[Juho Laatu]

On 1.10.2012, at 17.31, Michael Ossipoff wrote:

> Everyone here agrees that natural (sincere) circular ties would be
> rare.

Quite rare in typical political elections.

> Also, the choice is a lot less clear when there isn't a circular
> tie.

More difficult to think, but can be as clear.

> For those reasons, it matters much less what a rank method does
> when there isn't a CW.

Only because cycles are rare. But if we exclude that viewpoint, then quite as important.

> 
> I read that Condorcet(margins) fails the Plurality Criterion. Did you
> know that, Juho?

Not one of my favourite criteria (if any are as on/off criteria, since I like many criteria but do not require them to be met 100% if there are also other important targets to meet).

> 
> The Plurality Criterion is one of those "embarrassment criteria". It
> could be important because it could be used to easily defeat an
> enactment proposal.

I don't know how well that idea could be sold as negative marketing. There are many criteria that sound (or whose name sounds ;-) ) intuitive but that deserve a second look.

> That was why I ceased advocating MMPO.   ...along
> with burial strategy.
> 
> That's another thing about Margins: It has much more problem with
> burial and truncation to defeat a sincere CW, as compared with wv.

Margins are more vulnerable to some strategies than winning votes, but in some other strategies the balance is the other way around. What counts is vulnerability in real elections. Margins are quite good.

> And
> wv has a burial problem that its advocates are in denial about too.
> 
> By the way, speaking of denial, people at EM are in denial about the
> feasibility problems of rank-methods in general. I've discussed them
> enough that it isn't necessary to explain what I mean about that.

The best test would be to arrange competitive real life Condorcet elections. IRV seems to work fine, at least if we ignore the complaints about the sensibility of the elimination process. I think I may be in "denial" although I don't know yet what the key problem is that I deny :-).

Juho


> 
> Mike Ossipoff
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