[EM] Steph: Objectivity, relevance, equilibriumj

[MIKE OSSIPOFF]

For quite a while I haven't  had an opportunity to check the EM archives, 
but this message was
forwarded to my mailbox:

Steph wrote:

I still find Mr. Ossipoff analysis not objective

I reply:

I've always said that standards are entirely subjective. Your standards are 
different from mine, and
may your methods have great success with people who share your standards. 
The only way to
be wrong about standards is to say that your standards are best, or that 
someone else's standards
are wrong, ot that your standards are more objective than someone else's.

Steph continued:

...in the sense he claims margins and relative margins
can sometimes produce equilibria only when defensive
order-reversal is used.

I reply:

"Claims"? Do you claim otherwise? I've supported those claims with posted 
examples.
Margins methods and relative margins methods have situations in which the 
only Nash equilibria are
ones in which some voters use defensive order-reversal.

Steph continued:

Winning votes methods can sometimes produce different result
the same way depending on the fact voters decided to express
their full preferences or not.

I reply:

Yes, truncation can change the outcome with wv. Truncation can also change 
the outcome with
margins methods, relative margins methods, and with any rank balloting 
method. The difference
is that with wv, truncation won't steal the election from a 
majority-supported CW, as it will with
margins and relative margins.

Steph continued:

In the same way truncating your preferences can harm your favorite
using margins, giving your full preferences could harm your favorite
using winning votes.

I reply:

We've really got to have a FAQ about this. Gibbard & Satterthwaite have 
shown that, in every
nonprobabilistic method, there can be incentive for strategy. No one ever 
claimed that  that
doesn't apply to wv methods.  But we can choose what kinds of strategy we'll 
have incentive for,
and how badly we'll need them, and under what conditions, and whether or not 
all  the Nash
equilibria involve those strategies.

Steph continued:

Thus I see no relevance in verifying those "defensive strategies"
criterias,
when in the same time a method would not satisfy an "offensive strategy"

I reply:

If you'd like to propose new criteria, I suggest you define them, and then 
we can judge their
importance. What I and many other consider important is the need for 
defensive strategies. If
you believe that something else is more important, and have written criteria 
about it, please
clarify your different standard and post your offensve strategy criteria.

Steph continued:

Matching the pair ranking to the highest probability then
seems the fairest objective, so it leads to relative margins.

I reply:

Ok, here you're telling a standard that is more important to you. You aren't 
wrong.  To you, your
standard may well be more important.  But you're wrong, as I said, when you 
say that your
standard is more objective. You're also wrong when you say that your 
standard is more fair. Fairness
is judged in terms of some particular fairness standard.

Mike Ossipoff



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