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<div class="moz-cite-prefix">Mike,<br>
<br>
35 A>B<br>
25 B<br>
40 C<br>
<br>
<blockquote type="cite">A is the most favorite candidate without
majority pairwise opposition.</blockquote>
<br>
C: Fortunately Smith//MMPO meets Irrelevant Ballots
Independence, so let's make a slight <br>
change to the example so that there is no voted "majority" for
anyone to fetishise about.<br>
<br>
35 A>B<br>
25 B<br>
40 C<br>
21 D<br>
<br>
Smith//MMPO still elects A. Your explanation to the C
supporters as to why their favourite lost<br>
to A is now what?<br>
<br>
As is often the case with failures of the Plurality criterion, the
the example is also an outrageous <br>
failure of Later-no-Help. If the A supporters had truncated like
everyone else, then C would be<br>
the CW (and the only possible winner). <br>
<br>
Why should their ranking of B make their favourite (A) the
winner? Especially since the method <br>
has some random-fill incentive, why should we assume that their
ranking of B is sincere? What if their<br>
sincere preferences are just A or even A>C ?<br>
<br>
Part of your justification for Smith//MMPO is that it meets "Weak
CD". But in a recent post on that<br>
criterion you wrote:<br>
<br>
<blockquote type="cite">Not reassuring enough to be of much use.</blockquote>
<br>
C: So I assumed that it was an idea you were just toying with
before rejecting.<br>
<br>
<blockquote type="cite">Evidently MAM -like strategy is
incompatible with CD.</blockquote>
<br>
C: What is "MAM-like strategy" and what do you think is so good
("optimally unproblematic") about it?<br>
<br>
<blockquote type="cite">
<p dir="ltr">C: Also (like WV) it fails Mono-switch-plump.</p>
<p dir="ltr">M: That's widely accepted, if wv does it.</p>
</blockquote>
<br>
IRV and Benham also fail the criterion, but they (unlike all the
other proposed Condorcet methods I'm aware of) meet<br>
Unburiable Dominant Mutual Third (UDMT), which says that if the
winner X is a member of a set S of candidates who are voted<br>
strictly above all outside-S candidates on more than a third of
the ballots and who all pairwise beat all the outside-S <br>
candidates, then it isn't possible to cause the winner to change
from X to some outside-S candidate Y by just altering some <br>
ballots that vote Y above X.<br>
<br>
So one of my current standards is that a method should meet at
least one of Mono-switch-plump and UDMT.<br>
<br>
Is it one of your prejudices that anything that is "widely
accepted", should be accepted?<br>
<br>
Chris Benham<br>
<br>
<br>
On 9/22/2016 11:05 PM, Michael Ossipoff wrote:<br>
</div>
<blockquote
cite="mid:CAOKDY5BAhf=mPF4iUDzkfFhC1t72EC_RgLxdz3Cp5Hqqw5Pa=Q@mail.gmail.com"
type="cite">
<p dir="ltr"><br>
On Sep 21, 2016 7:50 PM, "C.Benham" <<a
moz-do-not-send="true" href="mailto:cbenham@adam.com.au">cbenham@adam.com.au</a>>
wrote:<br>
><br>
><br>
> Mike,<br>
><br>
> You recently wrote:<br>
>><br>
>> Smith//MMPO has replaced Plain MMPO as an advocacy of
mine.<br>
><br>
><br>
> Do you still advocate Smith//MMPO ?</p>
<p dir="ltr">Yes I do. Though it doesn't meet CD, it meets Weak
CD. </p>
<p dir="ltr">Evidently MAM -like strategy is incompatible with CD.<br>
><br>
> It seems very similar to Winning Votes (MAM, Schulze,
River, Smith//MinMax)...</p>
<p dir="ltr">Yes. If shares their optimally unproblematic
strategy.</p>
<p dir="ltr">You continued:</p>
<p dir="ltr">...except less decisive.<br>
(endquote)</p>
<p dir="ltr">It can be decisive. If 2 candidates have the same
max pairwise opposition, compare their next-largest pairwise
opposition...& so on.</p>
<p dir="ltr">You left out a property: Weak CD.<br>
</p>
<p dir="ltr">><br>
> 35 A>B<br>
> 25 B<br>
> 40 C<br>
><br>
> B>C 60-40, C>A 40-35, A>B 35-25. MPO
scores: A40 = B40 < C60<br>
</p>
<p dir="ltr">A wins.</p>
<p dir="ltr">> WV elects B...</p>
<p dir="ltr">...rewarding defection.</p>
<p dir="ltr"> but MMPO gives an A=B tie. </p>
<p dir="ltr">...solved as described above. A wins</p>
<p dir="ltr">You continue:</p>
<p dir="ltr"> B winning fails CD and A winning fails Plurality.</p>
<p dir="ltr">(endquote)</p>
<p dir="ltr">A is the most favorite candidate without majority
pairwise opposition.</p>
<p dir="ltr">If the Plurality Criterion says A shouldn't win, then
the Plurality Criterion is mistaken.</p>
<p dir="ltr">Plurality is a positional criterion. A positional
standard won't give the desired properties.<br>
</p>
<p dir="ltr">> Also (like WV) it fails Mono-switch-plump.</p>
<p dir="ltr">That widely accepted, if wv does it.<br>
</p>
<p dir="ltr">> 25 A>B<br>
> 26 B>C<br>
> 23 C>A<br>
> 22 C<br>
> 04 A<br>
><br>
> C>A 71-29, A>B 52-26, B>C 51-49. MPO
scores: C51 < B52 < A71<br>
><br>
> MMPO and WV elect C, but if the 4A ballots change to 4C
then they both elect B.<br>
><br>
> 25 A>B<br>
> 26 B>C<br>
> 23 C>A<br>
> 26 C</p>
<p dir="ltr">Of course, as you know, rank methods have faults like
that. Participation is another example.</p>
<p dir="ltr">Avoid them with Approval. </p>
<p dir="ltr">Michael Ossipoff</p>
<p dir="ltr">> C>A 75-26, A>B 48-26, B>C
51-49. MPO scores: B48 < C51 < A75.<br>
><br>
> In my view C, being both positionally dominant and
uncovered, is the prettiest winner.<br>
><br>
> Chris Benham<br>
><br>
</p>
<p class="" avgcert""="" color="#000000" align="left">No virus
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Checked by AVG - <a moz-do-not-send="true"
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Version: 2016.0.7797 / Virus Database: 4656/13063 - Release
Date: 09/22/16</p>
</blockquote>
<p><br>
</p>
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