[EM] Approval Voting and Long-term effects of voting systems

[Michael Ossipoff]

About IRV, I don't advocate IRV for current conditions. IRV's problems make
it entirely unsuitable for current conditions.

On Tue, Dec 20, 2016 at 5:35 AM, Kristofer Munsterhjelm <
km_elmet at t-online.de> wrote:

[Due to some incompatibility, it doesn't seem possible to bring the text up
to the top of this page. So it's necessary to scroll down to it, below] :


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> [quote]
> In the past, I've heard some Approval supporters go "well, you know the
> parties you absolutely do like and the parties you absolutely don't, so
> just approve the former and don't approve the latter". But this is
> another kind of patch. It works as long as that's true, but then fails
>
[endquote]

...if by "work" you mean "elect the best candidate you can get". But that
isn't the way to use Approval. Tactical voting, to try for the best
candidate you can get isn't what Approval is for.

I admit that many have a psychological need for that, and that's why
rank-methods might be necessary--but onlyif people are willing to go to the
trouble and expense needed to set up a rank-method.  ...a problem that
rank-method advocates seem to forget about.

In the polls that I've been doing, Approval has been the consistent big
winner.



> [when it's no longer the case. In a Burlington scenario, both IRV and
> Approval would have done well as long as there had been only two major
> parties. But when there're three on the line, IRV becomes confused...
>

Even if you insist on the goal of electing the best candidate possible,
Approval wouldn't have had a problem in Burlilngton, with only 3 winnable
candidates. The middle faction know that either they're the CWs, or one of
the other 2 has a 1st-choice majority.

In the latter case it doesn't matter what the middle voters do. In the
former case it's obvious that one of the wing-candidates needs the middle
candidate as comropromise.

Whichever of the 2 wing-candidates is the most likely to be smaller, hir
voters know that they need to approve Middle. For the reasons given above,
the middle faction know that they have no need to, and shouldn't, approve
anyone other than Middle.

That's if you're interested in tactical voting, to get the best candidate
you can.



> and
> the chicken problem appears in Approval.
>

No. Chicken dilemma, as we define it on EM, doesn't happen when there's a
middle CWs. The chicken-dilemma situation won't be common. And there are a
number of reasons why it won't be a problem.

There'd be sure to be talk about intention to chicken-dilemma defect. Its
intended victims would hear about it, and they'd announce that it will
backfire.
Defenders have the credibility-advantage in a chicken-dilemma situation.

Usually one of the 2 rival factions will be known to be larger than the
other. It would be understood that they won't approve the rival, because
their candidate is obviously the rightful winner.

Even if there's no prediction of which faction is larger, maybe one of them
is clearly more principled, ethical, moral or right. It would be
understood, and they'd clarify it, that they aren't going to approve the
less principled faction's candidate.

Defection would obviously have bad consequences later, when the defectors
wouldn't have their victims' help. In fact there's the Tit-For-Tat strategy:

Always do what the other faction did in the previous election (co-operate
or defect0.

But, disregarding the matter of future elections:

Forest suggested, here, a good solution to chicken-dilemma in Approval. I
recently posted a quantitative example to illustrate it.

For all of those reasons, chicken-dilemma in Approval isn't the problem
that opponents think it will be.


>
> =====
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> So I don't find the counter that you can just "approve of the candidates
> you like and not approve of the people you don't like" very persuasive.
>

That's because Kristofer insists on the need for electing the best
individual candidate that can be gotten. If you need that, then Approval
isn't for you. Stick with rank-methods. (But Approval is a lot more
feasible to implement, and a lot briefer to define, justify & explain--and
is the winner in two separate polls that I'm conducting.)



> This assumes that there will always be a clear delineation between the
> candidates the voters like and the candidates the voters don't like.
>

In this country, for the 99%, there is a vast merit, ethical, & moral *gulf
*between the progressive candidates and the Repugnocratic candidates.

You can hypothesize about other (Utopian) voting-situations. There's
nothing wrong with science-fiction.

...voting situations in which there's no strong bottom-set for the 99%,
because their bottom-set candidates, being unwinnable, are no longer in the
elections.

>
> So suppose that there will always be such a clear delineation. Then most
> systems (like Condorcet) that support equal rank and reduces to Approval
>


...expensive Approval.

But no, actually no that isn't true. Condorcet doesn't reduce to Approval,
because, unlike Approval, Condorcet fails FBC. If you've been convinced by
media that the winner can only ever be a Democrat or a Repugnican, then
guess what? You need to do whatever it takes to ensure that the Democrat
wins. With Condorcet, moving Jill up to top, alongside Democrat, can change
the winner from Democrat to Repugnican.

But yes, there *are* some good rank methods, methods that meet FBC.


> when everybody equal-ranks will work: just equal rank the acceptables
> and don't rank the rest.
>

No. Not good enough unless you're sure that sufficiently many people will
do the same. That's like saying to a Democrat overcompromiser: "Just vote
for Jill, because if enough do, she'll win."  The overcompromise has been
told, and believes, that only the Dem or Repug can win, and, believing
that, hir only right strategy in Condorcet is to rank Dem alone at top.

Kristofer continued:

On the other hand, suppose that there won't always be such a clear
delineation. Then Approval will start running into trouble
[endquote]

No, it's the person who thinks he needs to elect the best individual
candidate that he can get, who runs into trouble. But he makes his own
trouble for himself.

[quote]
and/or put a
burden on the voters when you get into a fuzzy territory.
[/quote]

Only for voters who insist on clinging to that burden.

If all the candidates are so good that there's no longer a strong
bottom-set for you, then that's a good thing. Don't make it into a problem
for yourself.

Say, with no strong bottom-set, the candidates have a uniform
merit-gradient, so there isn't even any obvious breakpoint. What a terrible
problem? No.

Maybe there's some region-subset within which you're fairly sure that the
approval-cuttoff should be. Maybe that region encompasses all of the
candidates. It doesn't matter.

If you don't know where the approval cutoff should be, if you don't know
what subset is the one you want to vote over the other, then it doesn't
matter. If you don' t know, then it doesn't matter.

If you cared, you'd know it.

So my reply? "You worry too much."





[quote]
In a
Burlington scenario, Approval could misjudge -- like IRV
[/quote]

[quote]
, except it
would misjudge in favor of a centrist rather than in favor of an
extremist, to the extent that the voters are risk averse and approve
more candidates than they would under optimal strategy.
[endquote]

If it looks to you like your wing-candidate has a majority, then you can be
sure that it looks to the opposite wing-factions that at least your
candidate is bigger than theirs. You know that they'll approve Middle
therefore. You don't need to, especially if you really have a majority. But
if you have a majority, and the other wing approves Middle, then your
majority candidate will still win.

Even if you feel the need for tactical voting, Approval is better than you
think.

[quote]
So my point is that in "easy to call" elections where all the voters
have a sharp delineation between who they like and not, most reasonable
methods get it right. The difference is that ranked methods don't force
you to vote as if that were the case when there *is* no such sharp
delineation.
[/quote]

As I said, in Approval, when it isn't clear which set you want to vote over
the others, then it doesn't really matter. Take a guess. One guess is as
good as another, if you don't feel a definite preference for a particular
approval-set, a particular approval-cutoff.


[quote]
On the other hand, in the scenarios where it's unclear what
society's preference is, like when there are multiple real contenders,
methods like Condorcet can have trouble. That's right, but so will
Approval.
[/quote]

When Approval is used in accordance with its merits & value, that isn't
"trouble" at all.

[quote]
The trouble manifests differently: in a Condorcet method, it permits
strategic voting if the voters know what they're doing. In Approval, it
increases the burden for honest voters
[/quote]

It definitely increases the "burden" on voters who insist on burdening
themselves with trying to elect the best candidate they could if they had
perfect information. As i said, you worry too much.


[quote]
(and the risk of a wrong result
if the honest voters don't pay attention).
[/quote]

A pproval elects the candidate who's satisfactory to the most voters.

Decide for yourself where to draw the line. If they're all satisfactory,
then just arbitrarily approve some better set. Don't worry about it.

[quote]
'Q: Do you support Approval over Condorcet since Condorcet has problems
with strategy?
A: Condorcet has problems with strategy. But Approval burdens the voters
even without strategy! ']
[/quote]

No, *you* burden *yourself*, if you think that you have to somehow,
tactically reliably elect the CWs in an Approval election.

But go for it. To each their own.

You could just vote to maximize the probability of electing from some
better-set (by approving only them). That's your strong top-set if there is
one. Or with a uniform merit-gradient of good candidates, you could
arbitrarily what you want to designate your best set. If you don't know, it
doesn't matter.

[quote]
And if Approval doesn't burden the honest voters, then neither do the
ranked methods.
[/quote]

Condorcet, by its FBC failure, causes a problem that Approval doesn't have.

Approval won't make someone vote SleazeCompromise over Favorite. Condorcet
will.

[quote]
Again, this kind of loops back to my concept of "manual DSV". Approval
can't do the impossible even though it seems to to do so, because
[Approval + whatever you do in your head to quantize the ballot] could
be considered just another voting method. If you do a fair comparison
between Approval and other methods by explicitly stating an algorithm
that does the quantization step for you, then the resulting quantized
Approval method is susceptible to strategy like every other.
[/quote]

...if you're obsessed with trying to elect the CWs.





[quote]
Consider a method like, say, MAM. This method passes the Smith
criterion, which means that it'll elect from the set of candidates where
all of them would win a one-on-one runoff with any of the candidates
outside the set. Another way of saying this is that it'll be uncertain
of whom to elect (in the absence of strategy) only among those who are
close to the median anyway. So it picks someone close to the median
without the honest voters having to accommodate the restrictions of the
system.
[/quote]

Condorcet & other rank-methods relieve the concerns of overcompromisers &
rival parties, and would likely avoid their worst voting-errors. Good rank
methods can give you some ability to choose among the candidates you most
importantly want to beat worse ones. But doing so increases the probability
of electing none of them.

But yes, with a good method like the MDDA versions, you can protect your
strong top-set as well as in Approval, while still voting some choice among
them.

And the best rank methods, in addition to meeting FBC, can also provide
easy, convenient & reliable ways of dealing with chicken-dilemma.

Those are nice luxuries, not necessities.   ...except for the
overcompromiser who needs rankings to keep from supporting sleaze.

I don't oppose rank methods. MDDA & MDDAsc are excellent luxury methods.

But Approval is incomparably easier to implement. Cost of implementation:
Zero.

Anyway, people aren't interested in rank-methods. They lose in my polls.
Approval wins. The only rank-method with any popularity is IRV. Probably
because of heavily funded promotion all around the country, wining & dining
leaders of parties & organizations.

Michael Ossipoff


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