[EM] FBC, center squeeze, and CD

[Michael Ossipoff]

I emphasize that I'm not saying that IRV is bad. I'm just saying that
MDDTR's faults certainly aren't worse than those of IRV.

And MDDTR offers a unique combination of valuable properties.

(...unique among methods that don't have a prohibitive problem and are
known to be implementable in large elections.)

Michael Ossipoff


On Mon, Nov 7, 2016 at 5:59 PM, Michael Ossipoff <email9648742 at gmail.com>
wrote:

> In my IRV Mono-Raise failure example:
>
> When I said:
>
> 33: A
> 29: B
> 30: C
>
> II meant:
>
> 33: A
> 29: B>C
> 30: C>A
>
> Michael Ossipoff
>
> On Mon, Nov 7, 2016 at 4:47 PM, Michael Ossipoff <email9648742 at gmail.com>
> wrote:
>
>> Chris, would your IBIFA interpretation of majority further improve MDDTR,
>> by keeping its FBC & CD, while avoiding the (unimportant) Mono-Add-Plump
>> failure?
>>
>> Michael Ossipoff
>>
>> On Mon, Nov 7, 2016 at 4:44 PM, Michael Ossipoff <email9648742 at gmail.com>
>> wrote:
>>
>>> I should re-state the definition of MDDTR, because we haven't discussed
>>> it for a while.
>>>
>>> Ii don't know who introuced MDDTR. Who introduced it?
>>>
>>> MDDTR stands for Majority Defeat Disqualification, Top Ratings.
>>>
>>> MDDTR:
>>>
>>> Voters can rank as many or as few candidates as they want to.
>>>
>>> Equal rankings allowed.
>>>
>>> 1. Disqualify any candidate who has a majority pairwise defeat, unless
>>> everyone has one.
>>>
>>> 2. The winner is the un-disqualified candidate top-ranked by the most
>>> voters.
>>>
>>> [end of definition]
>>>
>>> MDDTR meets FBC & CD, an has wv-like stratgy.
>>>
>>> The cost for that is that MDDTR fails Mono-Add-Plump. I've discussed
>>> what that is no worse than IRV's failure of Mono-Raise. If IRV can be
>>> popular in spite of Mono-Raise failure, and its favorite-burial need, then
>>> MDDTR's Mono-Add-Plump failure shouldn't have its importance & badness
>>> exaggerated.
>>>
>>> IRV is popular here. Then there's no reason why MDDTR couldn't or
>>> shouldn't be at least as popular.
>>>
>>> Michael Ossipoff
>>>
>>>
>>>
>>> On Mon, Nov 7, 2016 at 4:32 PM, Michael Ossipoff <email9648742 at gmail.com
>>> > wrote:
>>>
>>>>
>>>> Chris--
>>>>
>>>> You suggested that Mono-Add-Plump failure is worse than Mono-Raise
>>>> failure because people care more about their favorites, and because
>>>> Mono-Raise failure is simpler.
>>>>
>>>> 1. Caring about favorites:
>>>>
>>>> a) So you're saying that Mono-Raise failure can't happen when someone
>>>> sincerely moves their favorite to top?:
>>>>
>>>> IRV:
>>>>
>>>> 31: A
>>>> 2: B>A (sincere is A)
>>>> 29: B>C
>>>> 30: C>A
>>>>
>>>> 1st round totals:
>>>>
>>>> A = 31
>>>> B = 29 + 2 = 31
>>>> C = 30
>>>>
>>>> C is eliminated & transferss to A
>>>>
>>>> Now A has a 61 majority and wins.
>>>>
>>>> But then the 2 B>A voters decide to sincerely raise A to top:
>>>>
>>>> 33: A
>>>> 29: B
>>>> 30: C
>>>>
>>>> B gets eliminated, and transfers to C.
>>>>
>>>> Now C has a 59 majority and wins.
>>>>
>>>> b) You care about favorite? What about when you need to rank Comprmise
>>>> over favorite to keep worst from winning? We're all familiar with that. In
>>>> Burlington, the Republicans didn't do that, and their failure to
>>>> favorite-bury elected their last choice.
>>>>
>>>> Yes, this isn't a monotonicity failure, but you used caring about
>>>> Favorite as an advantage of IRV's Mono-Raise failure over MDDTR's
>>>> Mono-Add-Plump failure. But obviously IRV has a bigger problem for
>>>> Favorite. ...the reason why IRV was repealed in Burlington.
>>>>
>>>> So please, let's not use caring about Favorite as a reason to prefer
>>>> IRV with its Mono-Raise failure
>>>> & its favorite-burial need, to MDDTR's Mono-Add Plump failure.
>>>>
>>>> 2. Simplicity:
>>>>
>>>> What could be simpler than your need, in IRV, to bury your favorite to
>>>> help Compromise beat Worst:
>>>>
>>>> Sincere:
>>>>
>>>> 40: C
>>>> 25: B>C
>>>> 35: A>B
>>>>
>>>> A voters vote sincerely, and B, the CWv, gets eliminated & transfers to
>>>> C. C wins because the A voters didn't favorite-bury.
>>>>
>>>> Strategic:
>>>>
>>>> 40: C
>>>> 25: B>C
>>>> 35: B>A (sincere is A>B)
>>>>
>>>> Now B wins.
>>>>
>>>> That's as simple as it gets. Let's not say that MDDTR's look-bad
>>>> criterion-failurle is simpler than IRV's serious favorite-burial need.
>>>>
>>>> Yes, I'm talking about a problem that isn't a monotonicity problem. But
>>>> its at least as simple as MDDTR's Mono-Add-Plump problem, and is worse
>>>> because it's a practical strategy problem that makes people need to
>>>> favorite-bury.
>>>>
>>>> Michael Ossipoff
>>>>
>>>>
>>>> By sincerely raising A to top, you made A lose.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Mon, Nov 7, 2016 at 2:48 AM, Michael Ossipoff <
>>>> email9648742 at gmail.com> 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?
>>>>>
>>>>>
>>>>>>
>>>>>> 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
>>>>> thins 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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