[EM]Re: AWP versus AM (and DMC)

[Chris Benham]

James,

I'd written:
>One of the original justifications of the Plurality
>criterion was about inferring (conservatively)
>approval from rankings. 

And you responded:

> This can't be done. 

That is not the only or my favourite justification,
but don't you think its reasonable
to assume that voters "approve" the candidate they
rank in first place and not those
they rank equal-last?


You wrote (Sat.Apr.10):
"Chris:
>
>I find the phrase  "defeats consisting of..." an odd
>formulation with an unclear meaning. Arguably
"defeat"
>is just a label for a result which just is, and so
>doesn't really "consist of"  anything. 

Would the word "include" be more grammatical in place
of "consist of"?"

CB: Not really. It is possible to have an unclear
meaning without being ungrammatical.

You continued:
"Let me clarify my criterion. To keep things simple,
I'll call it the approval weighted pairwise (AWP)
criterion, since it's obviously designed just to
support AWP. Here's the definition:
"A voter expresses a strong preference for X over Y if
the voter approves X but not Y. If A pairwise beats B,
and there is no beatpath from B to A such that each
defeat includes as many or more strong preferences
than the A>B preference, then B shouldn't win." "

CB: I  think you need to specify  "..strong
preferences on the winning side".

>Maybe AWP  is a bit more strategy resistant than AP,

    I think that it is more than "a bit".

>but only at the huge cost of  flouting AP.

Your examples of  AWP resisting strategy better than
AP have not been very impressive to me (or I
gather,Ted).

"I could just as easily say that AM and DMC have a
huge cost in that they flout the AWP criterion."

CB: Not with any credibility, since the AWP criterion
was "obviously designed just to support" the method
(as you put it); and it doesn't seem to test for
anything that anyone was worrying about before  the
method was invented.
The AM criterion, on the other hand, is the perfectly
natural putting together of  two obviously fundamental
ideas: "that pairwise beaten candidates should tend to
lose" and "that more approved candidates should tend
to win"!

I  concede that the AWP method has its own mad logic,
and  that it succeeds somewhat at what it tries to do.
(And you can take that as my general reply to all
those arguments of yours that you complain that
I  "haven't replied to".)

But I think a lot of voters wouldn't understand the
AWP method or criterion, and some or many of those
that
do wouldn't be greatly reassured by the criterion.
On the other hand, I think most of the voters would
understand and appreciate the AP criterion, and
meeting it means  that  we always have some very 
simple and effective retort to potential complainers.

Regarding your example:

26: B>>D>K
22: B>>K>D
19: D>K>>B
6: D>>K>B
22: K>D>>B
5: K>>B>D

You wrote:
"By the way, if AWP elects Kerry, the Dean voters (who
by your logic have a huge and unanswerable complaint)
will not be interested in arguing for your AM method,
because it results in the election of Bush."

CB: No, but here the Dean voters can argue for  DMC 
or  Approval Elimination. The 6 D>>K>B voters might
think that AM would give their candidate a better
chance next time (I suppose assuming they think that
the 26 B>>D>K voters are sincere).


Chris  Benham











Find local movie times and trailers on Yahoo! Movies.
http://au.movies.yahoo.com