[EM] serious strategy problem in Condorcet, but not in IRV?

[Stephane Rouillon]

I understand but why burial strategy would be more damageable that
any defensive strategy ?
because it can lead to your disastrous C elected result ?
When you do such a behavioral study, you need to take in account human
behavior. Information about vote distribution is biased. Some persons do not
even know what they will vote for yet. In real life you would encounter every
cases: A>C>B, A=B>C, A>B?C so identifying all voters of the same opinion
would be very hard.  Even harder to regroup them or communicate which every
one.
And I do not speak about convincing them of the presicion of
your polls and the effect of your collective strategy... Finally, a lot of
people just
want to vote to express their will and they do not care about losing!

So I think electoral models using bullet votes are very more subject to
manipulation,
than Approval, and a lot more than ranking methods...

IMHO, FPTP allows manipulation attempts by one voter with a higher probability
of success
than other methods.

Steph

James Green-Armytage a écrit :

> >James,
> >your own example
> >Sincere preferences
> >46: A>B
> >44: B>A
> >5: C>A
> >5: C>B
> >shows a typical FPTP informational strategy opportunity.
> >You should inform Mr. Monroe about it...
> >It comes from the fact that FPTP forces C>B voters to choose
> >between C>A=B  or A>C=B (using universal ballots syntax).
> >You cannot assume the degree of information voters have to make their
> >decision,
> >it is a part of the strategical problems. Mr. Monroe sets this aside when
> >he makes his
> >analysis...
>
> Stephane,
>
> Please keep in mind that I am not really presenting Monroe's argument, but
> rather a somewhat bastardized interpretation thereof. However, Monroe
> isn't saying that IRV and plurality don't present strategy incentives. I
> think that that is obviously wrong. (Also, I doubt that Mike Ossipoff and
> Russ Paielli would have made such a statement, because on their web site
> they show plurality as failing numerous strategy criteria.) It is a
> particular kind of strategy that Monroe is concerned with, and one which
> he finds more disturbing than the kind of strategy you illustrate above.
>
> The problem with plurality (and to a lesser extent, with IRV, though not
> in this example) is that the C voters are forced to choose between a
> sincere vote and the lesser of two evils. In the terminology stated by
> Markus in a recent posting, this is the "compromising" strategy.
>
> I agree that it is a very serious problem to force voters to make this
> kind of compromising choices on a regular basis, as plurality clearly
> does. But what Monroe is concerned with is more so the "burying" strategy,
> and its possible consequences. In this particular example, what would
> worry him (I think) is that A and B voters will both try to get a bury
> each other, and will inadvertently elect C as a result, which I agree
> would be a public disaster.
>
> James
>
>
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