<div dir="ltr"><br>Chris--<br><br>I'd said:<br><br><div><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000"><div class="m_-7655863722893086320moz-cite-prefix"><span class=""><blockquote type="cite"><div>
<span class=""></span><br><span class="">
</span></div></blockquote></span><span class=""><blockquote type="cite">
<div>For #2, it really takes something with a lot of valuable
& otherwise-unobtainable properties, to justify replacing
Approval, Score or Bucklin with it.<br>
<br>
</div>
I suggest that only Plain MMPO qualifies.</blockquote></span></div></div></blockquote><div><br></div><div class="m_-7655863722893086320moz-cite-prefix">You replied:<br> <span class=""><br></span>
Say you ask people who are used to and/or like any of Approval,
Score, Bucklin, or plurality (aka FPP) or Top-Two Runoff or IRV
or Benham:<br>
<br>
(a) Would you accept a method that in a 3-candidate election with
20 million voters can elect a candidate that is voted above
equal-bottom<br>
on only two ballots?<br>
<br>
x: A<br>
1: C=A<br>
1: C=B<br>
x: B<br>
<br>
x = any number greater than 1. MMPO elects C.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">(enduote)<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">1. When I asked who is wronged, you said that the A voters are wronged, because, rightfully, it should be an A&B tie, and the A voters should have a 50% probability of their favorite winning. <br><br></div><div class="m_-7655863722893086320moz-cite-prefix">My answer to that was & is that the A voters have indicated that they don't consider B any better than C. They're indifferent between C and the other candidate whom they'd like to have a 50% probability of winning. Wronged? Sure. Significantly-wronged? No. It certainly can't be called an outrage.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">2, You make it sound as if what happened in that example is entirely the fault of the voting-system, and maybe the two A=C and B=C voters..<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">But it was done by the all A voters and B voters. In a method known to look only at pairwise opposition, those voters ensured that A & B will have as much pairwise opposition as anyone can have, because they refused to rank eachother's candidate over C.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">Refusal to co-operate with a rival can be a mistake in any method. It's hardly surprising if it's a mistake in MMPO too.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">So don't let the A voters & B voters convince, you when they whine about that result. ...the result of their refusal to co-operate with eachother.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">Think of it as the chicken-dilemma defection-blunder magnified.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">Ridiculous result? Sure. ...caused by ridiculous voting.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">...in an implausible example.<br><br>--------------------------------------------------------------------------------------------<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">That being said, I admit that the bad-example shows that MMPO has a wrong-looking-result-vulnerability.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">They go with methods that have deluxe properties. What else is new.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">The problem is that, of course, MMPO gets its unqualled properties-combination by looking only at pairwise opposition.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">For one thing, that means that it disregards how much positive support a candidate has. So it was possible to write a bad-example in which someone wins with practically no positive support...without that example's result seriously wronging anyone.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">Also, because it's _pairwise_ opposition, a candidate with two factions each ranking a different candidate over C, the method ignores the fact that C has _two_ candidates ranked over hir by a large number of voters, whereas A & B each have only one candidate ranked over them (by just one more voter). <br><br>MMPO doesn't count how many candidates are ranked over C, or the total number of voters who rank C lower. Thereby we get the wrong-looking result where C has both of the other candidates ranked over hir by a lot of people, but still beats A & B, each of which have just one candidate ranked over hir--by one more voter..<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">These are obvious inevitable results of looking only at pairwise opposition.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">But, even with those wrong-result vulnerabilities, the resulting bad-example doesn't significantly wrong anyone.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">Even though no serious wrong is done by those wrong-looking results, what can be done to avoid them?<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">* Rank some in-between compromise candidates over the worst one, ok? Is that too much to ask?<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">In that way, you rank eachother's candidate over the worst one, giving hir more people ranking those candidates over hir, to give hir more pairwise opposition than the candidates you like better.<br></div><div class="m_-7655863722893086320moz-cite-prefix"><br></div><div class="m_-7655863722893086320moz-cite-prefix">Set your rivalry aside and do that.<br></div><div class="m_-7655863722893086320moz-cite-prefix"><br>* Don't allow write-ins. Or, if you do allow write-ins, make sure that you rank compromises, not just your favorite, so that you're all voting eachother over whatever unknown write-in comes along, so that hir individual pairwise oppositions won't be less than those of the candidates you like more..<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">All the rank methods have strategy problems, to go with the deluxe properties that they bring. The more deluxe properties, the more kinds of wrong-looking results are possible. You get what you pay for.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">So you deal with those special vulnerabilities, as the price of the deluxe properties.<br><br></div><div class="m_-7655863722893086320moz-cite-prefix">Michael Ossipoff<br><br><br><br><br></div><div class="m_-7655863722893086320moz-cite-prefix"><br><br><br><br><br><br><br><br></div><div class="m_-7655863722893086320moz-cite-prefix"><br> <br></div><div class="m_-7655863722893086320moz-cite-prefix"><br><br><br><br></div><div class="m_-7655863722893086320moz-cite-prefix"><br><br></div><div class="m_-7655863722893086320moz-cite-prefix">
<br>
(b) Do you think it is fair and sensible that a voter who is only
interested in getting their favourite elected can increase the
chance of that<br>
happening by fully ranking (below top) all the other candidates at
random? <br><br> <br>
<br>
What response do you think you will get? <br>
<br>
I don't live in the US, but I would think that most people
wouldn't even believe that question (a) is serious, and that
anyone who tries to<br>
tell them that that example only "looks bad" would blow their
credibility.<br>
<br>
Chris Benham<br>
<br>
<br>
<br>
<br>
</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div bgcolor="#FFFFFF" text="#000000"><div><div class="h5">
<blockquote type="cite">
<div dir="ltr">Jameson--<br>
<br>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sat, Oct 29, 2016 at 11:16 AM,
Jameson Quinn <span dir="ltr"><<a href="mailto:jameson.quinn@gmail.com" target="_blank">jameson.quinn@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr"><br>
<div>....Here's my "ideal characteristics" for a
political single-winner election system, more or less
in descending order of importance:</div>
<div>
<ol>
<li>FBC<br>
</li>
</ol>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>Yes, I consider FBC to be #!.<br>
<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<ol>
<li><br>
</li>
<li>Handles center squeeze (ie, some form of
weakened Condorcet guarantee that's compatible
with FBC) <br>
</li>
</ol>
</div>
</div>
</blockquote>
<div>But maybe the goal of electing the CWs unnecessarily
complicates votiing. Maybe someday, there won't be a
bottom set, for most voters, and, with honest elections
& honest, open media, it will be clear who's the CWs.
But now, Approval's best strategy doesn't require that.
Brams pointed out that Approval's results can be better
than the CWs.<br>
<br>
</div>
<div>But, when it's desirable to elect the CWs, and it isn't
obvious who's the CWs, then the wv methods, and methods
with wv-like strategy (such as MMPO), are the methods that
make it easiest to protect the CWs.<br>
<br>
</div>
<div>Also, it should be noted that you can't be sure how
often there will be a CWs, under different and better
conditions.<br>
<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<ol>
<li><br>
</li>
<li>Relatively simple to explain<br>
</li>
</ol>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>Approval & Score are easy to explain. I've had
conversations in which only Approval & Score were
accepted as being plain & un-elaborate enough to be
acceptable..<br>
<br>
</div>
<div>You know that SARA & XA are complicated and not
easy to explain. I've tried explaining them.<br>
<br>
</div>
<div>MMPO?:<br>
<br>
</div>
<div>"The winner is the candidate who has fewest people
voting someone else over hir."<br>
<br>
</div>
<div>{...some same other candidate) <br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<ol>
<li><br>
</li>
<li>Minimal strategic burden</li>
</ol>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>We often hear it said that Approval has a large
strategic burden, but, for most people, with our current
candidate-lineup, there's nothing difficult about it:
Approve (only) the progressive candidates. That's optimal
for most people.<br>
<br>
</div>
<div>And if the time comes when, for most people, there
isn't a bottom-set, then that will be a happy
circumstance, in which it doesn't matter terribly anyway,
which candidate wins.<br>
<br>
</div>
<div>In such conditions, with honest elections and honest,
open media, it will likely be pretty obvious who's the
CWs, and, in the absence of tep-set/bottom-set, the best
strategy will be to just approve down to the CWs.<br>
<br>
</div>
<div>And, if there were no bottom-set, and if it happened
that it _wasn't_ clear who the CWs was, and it was 0-info,
then it would just be a matter of approving down to the
expected winning merit-level. Maybe, under those
conditions, that would be the candidate-mean. Or maybe
(as now) the estimated mean merit of what voters want
(which can be estimated by the candidates' merit-midrange,
if the election is 1D. ....but it might not remain 1D
under different and better conditions).<br>
<br>
</div>
<div>..but I repeat that, with only your former top-set
remaining as winnable candidates, it won't make as much
difference which one wins anyway.<br>
<br>
</div>
<div>People often consider Approval voting more difficult
than it is.<br>
<br>
<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<ol>
<li>Summable (ideally O(N), no worse than O(N²) in
practice, though I might accept some special
pleading for the use of prior polling to reduce to
O(N²).)<br>
</li>
<li>Handles CD, or at least, CD offensive strategies
don't in practice mess up the center squeeze
properties.<br>
</li>
</ol>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>MMPO meets Weak CD.<br>
<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<ol>
<li><br>
</li>
<li>Some arguable track record<br>
</li>
</ol>
</div>
</div>
</blockquote>
<div><br>
</div>
<div>Of course at EM we discuss two completely separate and
different method proposal choices:<br>
<br>
</div>
<div>1. Proposals to electorates who have only had
Plurality.<br>
<br>
2. Later proposals to replace one better voting system
with another.<br>
<br>
</div>
<div>If we're talking about #1, then there are only a few to
choose from:<br>
<br>
</div>
<div>Approval, Score, and Bucklin.<br>
<br>
<div><br>
</div>
I suggest that all 3 of those should be offered to
initiative-proposal committees, and that the public should
be polled, or consulted in "focus-groups", regarding which
of those 3 methods they'd accept<br>
<br>
<br>
</div>
<div>For #2, it really takes something with a lot of
valuable & otherwise-unobtainable properties, to
justify replacing Approval, Score or Bucklin with it.<br>
<br>
</div>
<div>I suggest that only Plain MMPO qualifies.<br>
<br>
</div>
<div><br>
</div>
<div><br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div>
<ol>
<li><br>
</li>
</ol>
<div> Approval does well on 1,3,4, and 6, is OK on 2,
and bad on 4 and 5.</div>
</div>
</div>
</blockquote>
<div><br>
<br>
</div>
<div>No. Contrary to what we so often hear, Approval doesn't
have a high strategic burden, as I discussed above. <br>
<br>
</div>
<div>Other than MMPO's CD, improvements over Approval by
more complicated methods are illusory.<br>
<br>
</div>
<div>And your standard #5 was summability and
count-complexity. Approval is precinct-summable, and its
count is the easiest and least computation-intensive,
among voting-systems.<br>
<br>
</div>
<div>Michael Ossipoff<br>
<br>
</div>
<br>
</div>
<br>
</div>
</div>
<br>
<br>
<p color="#000000" align="left"><br>
</p>
</blockquote>
<p><br>
</p>
</div></div></div>
<br>----<br>
Election-Methods mailing list - see <a href="http://electorama.com/em" rel="noreferrer" target="_blank">http://electorama.com/em</a> for list info<br>
<br></blockquote></div><br></div></div></div>