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<div class="moz-cite-prefix">On 10/19/2016 8:10 AM, Michael Ossipoff
wrote:<br>
<br>
<blockquote type="cite">It should be MMPO, rather than
Smith//MMPO, for one finalist-choosing method, and Approval,
Inferred-Approval, or Score for the other, because MMPO,
Approval, & Score meet FBC.</blockquote>
<br>
FBC won't survive any Push-over incentive (as I'm sure Kevin
Venzke would confirm).<br>
<br>
Chris Benham<br>
<br>
</div>
<blockquote
cite="mid:CAOKDY5B3D4S9j=uJL5a3b29yJaj00BwOm-Bft0E3efQ4yHYi9w@mail.gmail.com"
type="cite">
<p dir="ltr">It should be MMPO, rather than Smith//MMPO, for one
finalist-choosing method, and Approval, Inferred-Approval, or
Score for the other, because MMPO, Approval, & Score meet
FBC.</p>
<p dir="ltr">If Plain MMPO were replaced by anything else, Weak CD
would be lost.</p>
<p dir="ltr">If, for the other finalist-choosing method, Approval,
Inferred-Approval or Score were replaced by MAM or Beatpath,
then both finalist-choosing methods would share the same
strategic vulnerabilities.</p>
<p dir="ltr">Michael Ossipoff</p>
<div class="gmail_quote">On Oct 18, 2016 1:42 PM, "Forest Simmons"
<<a moz-do-not-send="true" href="mailto:fsimmons@pcc.edu">fsimmons@pcc.edu</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>I appreciate all of the great insights
from Kristofer, Chris Benham, and Michael
Ossipoff.<br>
<br>
</div>
Especially thanks to Kristofer for being a
good sport about my forwarding an email with
his private earlier input included. It was
too late when I realized I hadn't deleted
that part.<br>
<br>
</div>
<div>Intuitively, I think Chris is right that
Pushover is the biggest potential problem.
But I don't see an obvious example.<br>
</div>
<div><br>
</div>
Michael is right that we need to consider
other possibilities for the two base methods
for picking the finalists.<br>
<br>
</div>
I like MMPO or Smith//MMPO as one of them since
MMPO is one method that doesn't just reduce to
Approval when all candidates are ranked or rated
at the extremes. I think that the other method
should be one that does reduce to Approval at
the extremes, like River, MAM/RankedPairs, or
Beatpath/Tideman/Schulz. It could be a Bucklin
variant like MJ, Andy Jennings's Chiastic
Approval, or Jameson's MAS. <br>
<br>
Like Michael I think that Range itself gives
too much incentive to vote at the extremes on
the strategic ballots. Better to use Approval
or an approval variant so that the strategic
ratings are not unduly compressed for the other
base method. <br>
<br>
</div>
I like Kristofer's insights about the subtle
differences between the proposed "manual" version
in contradistinction to a DSV version that
automates strategy for the two methods based on
the first set of (perhaps somewhat
pre-strategized) ratings.<br>
<br>
</div>
In particular he pointed out how certain procedural
rules can externalize the paradoxes of voting. To a
certain extent Approval avoids bad properties by
externalizing them. The cost is the "burden" of the
voter deciding whom to approve. As Ron LeGrand has
so amply demonstrated, any time you try to automate
approval strategy in a semi-optimal way, you end up
with a non-monotone method. By the same token IRV
can be thought of as a rudimentary DSV approach to
plurality voting, so it should be no surprise that
IRV/STV is non-monotone.<br>
<br>
</div>
A better example, closer to the Kristofer's, idea is
Asset Voting. It externalizes everything, which makes
it impossible to contradict any nice ballot based
property. Because of this there is an extreme
resulting strategic burden, but in this case that
burden is placed squarely onto the shoulders of the
candidates, not the voters. Presumably the candidates
are up to that kind of burden since they are, after
all, politicians (in our contemplated public
applications).<br>
<br>
</div>
But this brings up another intriguing idea. Let one of
the two base methods be Asset Voting, so that the
sincere ballots decide between (say) the MMPO winner and
the Asset Voting winner.<br>
<br>
</div>
Thanks Again,<br>
<br>
</div>
Forest<br>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, Oct 18, 2016 at 12:32 PM,
Michael Ossipoff <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:email9648742@gmail.com" target="_blank">email9648742@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<p dir="ltr">If course the balloting for choosing
between the 2 finalists need only be rankings, to
show preferences between the 2 finalists, whoever
they turn out to be.</p>
<p dir="ltr">Some variations occurred to me. I'm not
saying that any of them would be better. I just
wanted to mention them, without any implication that
they haven't already occurred to everyone.</p>
<p dir="ltr">Both of the following possibilities have
disadvantages, in comparison to the initial
proposal:</p>
<p dir="ltr">1. What if, for the initial 2 counts, it
were a Score-count, in addition to the MMPO count.</p>
<p dir="ltr">One argument against that variation is
that a voter's inferred approvals are likely to be
more optimal for hir than the Score ratings on which
they're based.</p>
<p dir="ltr">2. For the 2 initial counts, what if the
MMPO count used a separate ranking, & the
Approval count used a separate set of
Approval-marks?</p>
<p dir="ltr">Would that make it easier for Chris's
pushover strategist?</p>
<p dir="ltr">What other positive & negative
results?</p>
<p dir="ltr">One possible disadvantage that occurs to
me is that overcompromising voters might approve
lower than than necessary, if the approval were
explicitly voted. ...in comparison to their
ratings-which tend to soften voting errors.</p>
<p dir="ltr">So far, it appears that the initial
proposal is probably the best one.</p>
<span class="m_2236720442496602401HOEnZb"><font
color="#888888">
<p dir="ltr">Michael Ossipoff</p>
</font></span>
<div class="m_2236720442496602401HOEnZb">
<div class="m_2236720442496602401h5">
<div class="gmail_quote">On Oct 17, 2016 1:49 PM,
"Forest Simmons" <<a moz-do-not-send="true"
href="mailto:fsimmons@pcc.edu" target="_blank">fsimmons@pcc.edu</a>>
wrote:<br type="attribution">
<blockquote class="gmail_quote" style="margin:0
0 0 .8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div dir="ltr">
<div>
<div>
<div>
<div>Kristofer,<br>
<br>
Perhaps the way out is to invite two
ballots from each voter. The first
set of ballots is used to narrow
down to two alternatives. It is
expected that these ballots will be
voted with all possible manipulative
strategy ... chicken defection,
pushover, burial, etc.<br>
<br>
</div>
The second set is used only to decide
between the two alternatives served up
by the first set.<br>
<br>
</div>
A voter who doesn't like strategic
burden need not contribute to the first
set, or could submit the same ballot to
both sets.<br>
<br>
</div>
<div>If both ballots were Olympic Score
style, with scores ranging from blank
(=0) to 10, there would be enough
resolution for all practical purposes.
Approval voters could simply specify
their approvals with 10 and leave the
other candidates' scores blank.<br>
<br>
</div>
<div>There should be no consistency
requirement between the two ballots.
They should be put in separate boxes and
counted separately. Only that policy
can guarantee the sincerity of the
ballots in the second set.<br>
<br>
</div>
<div>In this regard it is important to
realize that optimal perfect information
approval strategy may require you to
approve out of order, i.e. approve X and
not Y even if you sincerely rate Y
higher than X. [We're talking about
optimal in the sense of maximizing your
expectation, meaning the expectation of
your sincere ratings ballot, (your
contribution to the second set).] <br>
<br>
</div>
<div>Nobody expects sincerity on the first
set of ballots. If some of them are
sincere, no harm done, as long as the
methods for choosing the two finalists
are reasonable.<br>
<br>
</div>
<div>On the other hand, no rational voter
would vote insincerely on hir
contribution to the second set. The
social scientist has a near perfect
window into the sincere preferences of
the voters.<br>
<br>
</div>
<div>Suppose the respective finalists are
chosen by IRV and Implicit Approval,
respectively, applied to the first set
of ballots. People's eyes would be
opened when they saw how often the
Approval Winner was sincerely preferred
over the IRV winner.<br>
<br>
</div>
<div>Currently my first choice of methods
for choosing the respective finalists
would be MMPO for one of them and
Approval for the other, with the
approval cutoff at midrange (so scores
of six through ten represent approval).<br>
<br>
</div>
<div>Consider the strategical ballot set
profile conforming to<br>
<br>
</div>
<div>40 C<br>
</div>
<div>32 A>B<br>
</div>
<div>28 B<br>
<br>
</div>
<div>The MMPO finalist would be A, and the
likely Approval finalist would be B,
unless too many B ratings were below
midrange.<br>
<br>
</div>
<div>If the sincere ballots were<br>
<br>
</div>
<div>40 C<br>
</div>
<div>32 A>B<br>
</div>
<div>28 B>A<br>
<br>
</div>
<div>then the runoff winner determined by
the second set of ballots would be A,
the CWs. The chicken defection was to
no avail. Note that even though this
violates Plurality on the first set of
ballots, it does not on the sincere set.<br>
<br>
</div>
<div>On the other hand, if the sincere set
conformed to<br>
<br>
</div>
<div>40 C>B<br>
</div>
<div>32 A>B<br>
</div>
<div>28 B>C<br>
<br>
</div>
<div>then the runoff winner would be B,
the CWs, and the C faction attempt to
win by truncation of B would have no
effect. A burial of B by the C faction
would be no more rewarding than their
truncation of B.<br>
<br>
</div>
<div>So this idea seems to take care of
the tension between methods that are
immune to burial and methods that are
immune to chicken defection.<br>
<br>
</div>
<div>Furthermore, the plurality problem of
MMPO evaporates. Even if all of the
voters vote approval style in either or
both sets of ballots, the Plurality
problem will automatically evaporate; on
approval style ballots the Approval
winner pairwise beats all other
candidates, including the MMPO candidate
(if different from the approval winner).<br>
<br>
</div>
<div>What do you think?<br>
<br>
</div>
<div>Forest<br>
</div>
<div><br>
<br>
</div>
<div><br>
</div>
<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sun, Oct 16,
2016 at 1:30 AM, Kristofer Munsterhjelm
<span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:km_elmet@t-online.de"
target="_blank">km_elmet@t-online.de</a>></span>
wrote:<br>
<blockquote class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex"><span>On
10/15/2016 11:56 PM, Forest Simmons
wrote:<br>
> Thanks, Kristofer; it seems to
be a folk theorem waiting for
formalization.<br>
><br>
> That reminds me that someone
once pointed out that almost all of
the<br>
> methods favored by EM list
enthusiasts reduce to Approval when
only top<br>
> and bottom votes are used, in
particular when Condorcet methods
allow<br>
> equal top and multiple
truncation votes they fall into this
category<br>
> because the Approval Winner is
the pairwise winner for approval
style<br>
> ballots.<br>
><br>
> Everything else (besides
approval strategy) that we do seems
to be an<br>
> effort to lift the strategical
burden from the voter. We would
like to<br>
> remove that burden in all
cases, but at least in the zero info
case.<br>
> Yet that simple goal is
somewhat elusive as well.<br>
<br>
</span>Suppose we have a proof for
such a theorem. Then you could have a<br>
gradient argument going like this:<br>
<br>
- If you're never harmed by ranking
Approval style, then you should do so.<br>
- But figuring out the correct
threshold to use is tough (strategic
burden)<br>
- So you may err, which leads to a
problem. And even if you don't, if<br>
the voters feel they have to burden
their minds, that's a bad thing.<br>
<br>
Here, traditional game theory would
probably pick some kind of mixed<br>
strategy, where you "exaggerate"
(Approval-ize) only to the extent that<br>
you benefit even when taking your
errors into account. But such an<br>
equilibrium is unrealistic (we'd have
to find out why, but probably<br>
because it would in the worst case
require everybody to know about<br>
everybody else's level of bounded
rationality).<br>
<br>
And if the erring causes sufficiently
bad results, we're left with two<br>
possibilities:<br>
<br>
- Either suppose that the method is
sufficiently robust that most voters<br>
won't use Approval strategy (e.g. the
pro-MJ argument that Approval<br>
strategy only is a benefit if enough
people use it, so most people<br>
won't, so we'll have a correlated
equilibrium of sorts)<br>
<br>
- That any admissible method must have
a "bump in the road" on the way<br>
from a honest vote to an Approval
vote, where moving closer to<br>
Approval-style harms the voter. Then a
game-theoretical voter only votes<br>
Approval style if he can coordinate
with enough other voters to pass the<br>
bump, which again is unrealistic.<br>
<br>
But solution #2 will probably destroy
quite a few nice properties (like<br>
monotonicity + FBC; if the proof is by
contradiction, then we'd know<br>
some property combinations we'd have
to violate). So we can't have it all.<br>
</blockquote>
</div>
<br>
</div>
</div>
</blockquote>
</div>
</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</blockquote>
</div>
<br>
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