[EM] FBC, center squeeze, and CD

Tue Nov 8 14:05:34 PST 2016

(Replying farther down)

On Nov 8, 2016 8:22 AM, "C.Benham" <cbenham at adam.com.au> wrote:
>
> On 11/7/2016 6:18 PM, Michael Ossipoff wrote:
>>
>>
>>
>> On Sun, Nov 6, 2016 at 11:24 PM, C.Benham <cbenham at adam.com.au> wrote:
>>>
>>> On 11/7/2016 6:07 AM, Michael Ossipoff wrote:
>>>>
>>>> ...someone could say. "You didn't just favor X. You added a ballot,
thereby spoiling a majority. It has nothing to do with the fact that you
voted for X. You could have plumped for any of various candidates, and the
effect would have been exacsly the same."
>>>
>>>
>>> "Someone" could say that, but it wouldn't make any sense.
>>
>>
>> But how so?
>>
>
>
>
> C: Failing mono-add-plump is as stupid as a quasi-"intelligent" device
can be, in a pure and starkly obvious way, and with the lamest possible
excuse.
>
> The algorithm/device decides that X should win, and then receives some
more ballots that contain nothing whatsoever but the pure and simple
message:
> "You are right! X should win" and responds with the bizarre malfunction
"I've changed my mind, Y should win"

(endquote)

...& you're saying when you raise X to top in your ballot, you aren't
saying that X should win?

(You continued) :

and offers the nonsensical excuse "Hey those
> extra ballots didn't just say that X should win. They also increased the
total number of ballots!".

...which would have spoiled X's win if you'd plumped for any if various
other candidates. The fact that you favored X had nothing to do with how or
why your ballot made X lose.

(Replying farther down)

>
>
>> C: What (arguably) desirable properties (or criterion compliances)  are
incompatible with meeting Mono-add-Plump?
>>
>> Mike: FBC, CD, & wv-like strategy are evidently require failing
Mono-Add-Plump, or having MMPO's Hitler-with-2-votes problem.
>>
>> With MDDTR, the price of FBC, CD & wv-like strategy is Mono-Add-Plump.
>
>
> C: There are methods that meet  FBC and CD and mono-add-plump. So your
proposition boils down to saying that it's worth giving up compliance with
> mono-add-plump just to gain "wv-like strategy".
>
> That argument is impossible to make.

(endquote)

But how so?

(You wrote) :

And it isn't clear to me that "wv-like strategy" is even something we
should take if it was free.

(endquote)

In Benham, Woodall, ICT, & probably many or most pairwise-count methods,
the CWs has no protection from burial, or even from innocent, non-strategic
truncation.

With wv-like strategy, truncation from one side can't take victory from the
CWs & give it to the truncators' candidate.

...and plumping by the CWs's voters makes it impossible for burial to
succeed. In fact, the mere threat of that plumping can deter burial.

Wv-like strategy improves, too, on the situation in Bucklin, where plumping
by the CWs's voters is just plain needed. (compared to wv-like strategy,
where the mere threat of plumping can be enough).

Michael Ossipoff
>
> Chris Benham
>
>
>
>
>>
>>>
>>>
>>>> But you can't say anything like that to to explain why X lost when I
raised hir in my ranking. In that instance, making the ballot-set more
favorable to X is the _only_ thing that I'm doing.
>>>
>>>
>>> Increasing the turnout is generally regarded as a good thing.  If the
method used was one of the mono-raise failing methods I like (such as IRV
and Benham), I would say:
>>>
>>> "Unfortunately it isn't possible for voting methods to have every
desirable property (because some of those properties are mutually
incompatible), and this method economises
>>> by not meeting mono-raise.
>>
>>
>> Exactly. The more properties, important desirable ones, a method
provides, the more of a cost there is, in terms of "embarrassment
criteria", "could-look-bad".
>>
>> So it's a matter of what you're getting in terms of the
"could-look-bad", and whether that could-look-bad could be bad in a
practical way. As you suggested, MMPO's "Hitler-with-2-votes" would be bad
news, and, as you suggested, is more than a "look-bad".
>>
>> But the Mono-Raise failure of Benham, Woodall & IRV is only a
could-look-bad. It never bothered me, and never stopped me from saying good
things about those methods.
>>
>> Likewise the lesser look-bad of MDDTR, when it fails Mono-Add-Plump.
>>
>> MDDTR meets FBC & CD, and it has wv-like strategy.
>>
>> ...the same advantages that MMPO has.
>>
>> ...at the cost of Mono-Add-Plump.
>>
>> You like IRV, Benham & Woodall. Lots of people here love IRV. I don't
reject those methods, though they aren't my main proposals, because of FBC,
and the fact that there's nothing the CWs's voters can do to protects hir
from losing, and the fact that Benham & Woodall are pairwise-count methods
very vulnerable to pairwise-count offensive strategy, and innocent,
nonstrategic truncation.
>>
>> If you aren't majority-favored, the elimination of the CWs is
disadvantages for you. But, in Bucklin, sometimes it might not be known who
the CWs is, and s/he might not defenseiveliy plump, and so s/he (& you too)
lose anyway, even though it isn't IRV. I don't know that the Bucklin
failure that I just described will be rarer than the IRV failure that I
just described. And IRV brings some big advantages for people who are
majority-favored...MMC, CD, LNHa, LNHe.
>>
>> If your candidate is big enough to eliminate the CW, then s/he's big
enough that s/he's fairly well-known, and that CW's voters would know
something about hir, and would be unlikely to reject hir & transfer the
other way when s/he's close enough to what you want that you'd prefer to
elect hir.
>>
>> So I don't reject IRV--I just don't emphasize it as a proposal.
>>
>> Anyway, as I said, lots of people here love IRV, and its Mono-Raise
failure doesn't seem to hurt its popularity. You like IRV, and its
Mono-Raise failure doesn't put you off from it. I agree with you on that.
>>
>> And, for the same reason, we needn't & shouldn't be put off by MDDTR's
Mono-Add-Plump failure.
>>
>>
>>>
>>>
>>> But generally speaking people care most about their favourites
>>
>>
>> True.
>>
>>>
>>> , and IRV meets not only mono-add-plump but also mono-add-top. It's
true that after the election
>>> some of losing candidate X's supporters could complain "If we hadn't
top-ranked X, then X would have won" but that is unlikely to be noticed and
of course isn't
>>> true of all (or anything like all) of X's supporters.  So the X
supporters as a whole could complain "If we had been well informed and
coordinated we could have
>>> used a mixed strategy (with not all of us voting the same way) and
elected X."
>>>
>>> But if voters accept the method as fair and legitimate then that
"complaint" won't be taken seriously or get much sympathy.
>>
>>
>> ...as with MDDTR.
>>
>>>
>>>
>>> Just as no quasi-intelligent device should be so "stupid" as to be
confused by the very simple and spectacular MMPO failure example, neither
should it be
>>> confused by the very very simple mono-add-plump scenario.
>>
>>
>> ...or the fact that in IRV you can make someone lose by ranking them
higher?
>>
>>>
>>>
>>> What (arguably) desirable properties (or criterion compliances)  are
incompatible with meeting Mono-add-Plump?
>>
>>
>> FBC, CD, & wv-like strategy are evidently require failing
Mono-Add-Plump, or having MMPO's Hitler-with-2-votes problem.
>>
>> With MDDTR, the price of FBC, CD & wv-like strategy is Mono-Add-Plump.
That's a very small price, arguably less than IRV's Mono-Raise failure
(though I note that you mentioned that Mono-Add-Plump is about a favorite).
>>
>> Michael Ossipoff
>>>
>>>
>>> Chris Benham
>>>
>>>
>>>> Ok, thanks, Chris, for settling that matter. I guess we have to
reluctantly give up Conditional Bucklin.
>>>>
>>>> But it would have been strategically great!
>>>>
>>>> Now, here's a question on a related topic:
>>>>
>>>> Say I arrive at the polling-place late. Before I arrive X is winning.
I show up & plump for X, and that causes X to lose.
>>>>
>>>>
>>>> ...is that worse than if I raise X in my ranking, and that causes X to
lose?
>>>>
>>>> If so, why?
>>>>
>>>> It seems to me that the latter is worse than the former.
>>>>
>>>> I if show up late and plump for X, I'm doing two things: I'm adding a
ballot, and I'm voting that ballot in a way that clearly should favor X.
>>>>
>>>> If i angrily complain, "Hey, how come, when I arrived and plumped for
X, that made X lose??!"
>>>>
>>>> ...someone could say. "You didn't just favor X. You added a ballot,
thereby spoiling a majority. It has nothing to do with the fact that you
voted for X. You could have plumped for any of various candidates, and the
effect would have been exacsly the same."
>>>>
>>>> But you can't say anything like that to to explain why X lost when I
raised hir in my ranking. In that instance, making the ballot-set more
favorable to X is the _only_ thing that I'm doing.
>>>>
>>>> So plainly violating Mono-Raise is worse than violating
Mono-Add-Plump.
>>>>
>>>> Michael Ossipoff
>>>>
>>>>
>>>>
>>>> On Sun, Nov 6, 2016 at 10:27 AM, C.Benham <cbenham at adam.com.au> wrote:
>>>>>
>>>>> The example I just posted of  "IBIFA with an anti-defection device"
failing FBC I'm afraid also works for both Mike's suggested
>>>>> "Conditional Bucklin" and Forest's suggested "TopMiddleBottom".
>>>>>
>>>>> 20: F=C >>B
>>>>> 07: F > C=B   (or, for the sake of Forest's method suggestion, F >>
C=B)
>>>>> 25: B
>>>>> 48: W
>>>>>
>>>>> All three of these methods elect W, but if the 20 F=C >> B voters
change their rating of F from Top to Middle or Bottom
>>>>> then the winner changes to B.
>>>>>
>>>>> Chris Benham
>>>>>
>>>>>
>>>>>
>>>
>>
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>
>
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