[EM] BTR-like phrasing of Benham

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[EM] BTR-like phrasing of Benham

Kristofer Munsterhjelm-3
Here's a BTR-IRV-like phrasing of Benham. The ballot counters would
probably not appreciate the extra work, but there's a benefit that it
can easily be used in STV as well:

- When choosing a candidate to eliminate, consider the two candidates A
and B with fewest first preference votes (A having fewer than B). If A
wins a runoff against every other remaining candidate, eliminate B;
otherwise, eliminate A.

This works because if, after some eliminations, X is the CW among the
remaining candidates, then X will never be eliminated after that point.
Thus the candidate who remains until the end is the Benham winner. It
works in STV as well because as long as the election and surplus
distribution based on first preferences work the way they do in STV, the
method passes Droop proportionality, no matter what candidates are
eliminated.

Similarly, transplanting the BTR elimination mechanism onto STV will
preserve Droop proportionality. I think Rob suggested that the
eliminated candidate for STV-ME (BTR-IRV's STV analog) should be the
loser of a Condorcet method's election among the (s+1) candidates with
the fewest votes, where s is the number of seats remaining to elect
candidates to. That strikes me as a little too complex, though.

Just basing the method on globally preserving the CW is easier, although
it might produce somewhat of a centrist bias within each solid
coalition. Then again, it might not, given how the surplus distribution
works. E.g. the first solid coalition would elect a global CW if there
is one among it; but then everybody who voted for this global CW in
first place after eliminations would be deweighted, so that later "CWs"
would be biased in the opposite direction, somewhat. It's hard to tell.

Even if it's centrist-biased, that might not be a bad thing. See e.g.
arguments for deliberately giving the center greater weight in an
otherwise proportional system to limit unfair kingmaker scenarios.
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Re: [EM] BTR-like phrasing of Benham

Richard Lung
I see you are still eliminating.
It reminds of the Daleks: "Exterminate, Exterminate! EXTERMINATE!"

(It's not democracy.)

Richard L.


On 06/12/2019 23:09, Kristofer Munsterhjelm wrote:

> Here's a BTR-IRV-like phrasing of Benham. The ballot counters would
> probably not appreciate the extra work, but there's a benefit that it
> can easily be used in STV as well:
>
> - When choosing a candidate to eliminate, consider the two candidates A
> and B with fewest first preference votes (A having fewer than B). If A
> wins a runoff against every other remaining candidate, eliminate B;
> otherwise, eliminate A.
>
> This works because if, after some eliminations, X is the CW among the
> remaining candidates, then X will never be eliminated after that point.
> Thus the candidate who remains until the end is the Benham winner. It
> works in STV as well because as long as the election and surplus
> distribution based on first preferences work the way they do in STV, the
> method passes Droop proportionality, no matter what candidates are
> eliminated.
>
> Similarly, transplanting the BTR elimination mechanism onto STV will
> preserve Droop proportionality. I think Rob suggested that the
> eliminated candidate for STV-ME (BTR-IRV's STV analog) should be the
> loser of a Condorcet method's election among the (s+1) candidates with
> the fewest votes, where s is the number of seats remaining to elect
> candidates to. That strikes me as a little too complex, though.
>
> Just basing the method on globally preserving the CW is easier, although
> it might produce somewhat of a centrist bias within each solid
> coalition. Then again, it might not, given how the surplus distribution
> works. E.g. the first solid coalition would elect a global CW if there
> is one among it; but then everybody who voted for this global CW in
> first place after eliminations would be deweighted, so that later "CWs"
> would be biased in the opposite direction, somewhat. It's hard to tell.
>
> Even if it's centrist-biased, that might not be a bad thing. See e.g.
> arguments for deliberately giving the center greater weight in an
> otherwise proportional system to limit unfair kingmaker scenarios.
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>

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Re: [EM] BTR-like phrasing of Benham

Kristofer Munsterhjelm-3
On 07/12/2019 12.22, Richard Lung wrote:
> I see you are still eliminating.
> It reminds of the Daleks: "Exterminate, Exterminate! EXTERMINATE!"
>
> (It's not democracy.)

Tell that to the IRVists :-) I have plenty of non-elimination methods too.

(And your quote reminds me of a snarky robot sidekick from a game; he
says that in jest at one point.)
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Re: [EM] BTR-like phrasing of Benham

Richard Lung
"Tell that to the IRVists" is not an argument. You could say that about any system partisans.

Richard L.

On 07/12/2019 14:55, Kristofer Munsterhjelm wrote:

> On 07/12/2019 12.22, Richard Lung wrote:
>> I see you are still eliminating.
>> It reminds of the Daleks: "Exterminate, Exterminate! EXTERMINATE!"
>>
>> (It's not democracy.)
> Tell that to the IRVists :-) I have plenty of non-elimination methods too.
>
> (And your quote reminds me of a snarky robot sidekick from a game; he
> says that in jest at one point.)
>

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Re: [EM] BTR-like phrasing of Benham

Kristofer Munsterhjelm-3
On 07/12/2019 19.32, Richard Lung wrote:
> "Tell that to the IRVists" is not an argument. You could say that about
> any system partisans.

It's not an argument against the claim "elimination is bad". It's an
explanation of the context. At this point, I think the best way to
highlight that context is simply to quote Robert:

> So if I had my druthers, it would not be BTR-STV.  But here I am in Burlington Vermont of all places.

In other words, if you have to choose a method in a vacuum, it should
not be BTR-STV. If you have to choose a method in a vacuum and the
electorate is strategic and you want to use Benham, you should not use
my language to implement it.

The whole point of the language is to produce something that is close
enough to IRV to be acceptable to the partisans or partisan-friendly. If
you didn't have that constraint, you wouldn't need to do that. But for
people who are in that situation, my language could be useful.

(Now, if I were to argue in favor of or against elimination as a
mechanism, I would've said something entirely different :-)
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Re: [EM] BTR-like phrasing of Benham

Richard Lung
Alright, fair point.
Thankyou for troubling to explain.

I think American electoral reform is going adrift, in preference without
proportion, as others go adrift in the other direction (proportion
without preference).
An either a vote reform or a count reform will not solve the problem of
representation.

Richard L.


On 07/12/2019 20:22, Kristofer Munsterhjelm wrote:

> On 07/12/2019 19.32, Richard Lung wrote:
>> "Tell that to the IRVists" is not an argument. You could say that about
>> any system partisans.
> It's not an argument against the claim "elimination is bad". It's an
> explanation of the context. At this point, I think the best way to
> highlight that context is simply to quote Robert:
>
>> So if I had my druthers, it would not be BTR-STV.  But here I am in Burlington Vermont of all places.
> In other words, if you have to choose a method in a vacuum, it should
> not be BTR-STV. If you have to choose a method in a vacuum and the
> electorate is strategic and you want to use Benham, you should not use
> my language to implement it.
>
> The whole point of the language is to produce something that is close
> enough to IRV to be acceptable to the partisans or partisan-friendly. If
> you didn't have that constraint, you wouldn't need to do that. But for
> people who are in that situation, my language could be useful.
>
> (Now, if I were to argue in favor of or against elimination as a
> mechanism, I would've said something entirely different :-)
>

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