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

[Michael Ossipoff]

Daniel--

Well-said.

Short answer: You're right. There are a lot of reasons why Approval is the
best.

As you suggested, people in this country are subject to the
"lesser-of-2-evils problem". With Approval, even if someone feels a need to
fully support a bad compromise like Hillary Clinton, at least s/he has no
reason to not also approve hir favorite, Jill.Stein.

Some people complain that Approval prevents that person from expressing
their preference for Jill over Hillary.

What they're missing is that there are some people who, with any method
that fails FBC, would feel forced to rank Hillary alone in 1st place, just
as you said.

FBC (Favorite Burial Criterion) is a criterion that says:

To top-vote a candidate means to not vote anyone over hir, and to vote hir
over someone.

Say you top-vote some candidates, and one of them would win. But then you
move another candidate up to top, and the result is that now _none_ of your
top-voted candidates wins (including the new one), and now the winner is
someone you didn't top-vote.

FBC says that shouldn't happen. Raising an additional candidate to top
shouldn't change the winner from someone you top-voted to someone you
didn't top-vote.

In other words, it should be completely safe to top-vote Favorite, without
fear that doing so could change the winner from (top-voted) Compromise to
Worst.

It's obvious that Approval meets FBC. Overcompromisers badly need a voting
system that meets FBC.

Approval isn't the only method that meets FBC, but it's of course by far
the most easily-implemented voting system that's any good.

There are other reasons why Approval is the best:

If you're a progressive (and everyone in the 99% would benefit tremendously
from an honest, progressive government), then there are two blatantly,
sharply-distinct sets of candidates: Progressives and Republocrats. It's a
matter of honest & progressive, vs corrupt, dishonest and corporate-owned.

That's an instance of what I call a "strong top-set" and a "strong
bottom-set", defined as follows:

A strong top-set and a strong bottom-set are two sets of candidates such
that the merit difference _between_ the sets is incomparably more important
than the merit difference _within_ the sets.

In other words the merit difference within the sets is entirely negligible
in comparison to the merit difference between the sets.

Your goal, then, is just to elect from your strong top-set.

That's innomparably more important than choosing among your strong top-set,
or trying to keep one strong bottom-set member from winning instead of
another strong bottom-set member.

...and of course it's the strong top-set that you prefer to the strong
bottom-set.

Approval could be called "Set-Voting". It's a perfect match for what you
want to do: Maximize the probability of electing from your strong top-set.

Approval asks the right question.

For the person who has a strong top-set and a strong bottom-set, it's
possible to say what the objective best method is: It's Approval.

Now, some people want to have it both ways. They want to elect from their
strong top-set, but they also want the luxury of choosing _among_ that set.

It doesn't work that way. You can't have it both ways.

If a voting-system allows you a choice between casting  an effective
approval-set vote, or ranking the candidates in order of preference , and
you choose the latter, then you're increasing the probability of electing
from your strong bottom-set.

So, rank methods don't improve on Approval. As I said, improvements on
Approval are illusory.

Well, the nearest thing to a "problem" that Approval has is the
chicken-dilemma, and some rank methods can avoid the chicken-dilemma.

That's the only genuine excuse to use a rank-method. There are methods that
both avoid chicken-dilemma, and meet FBC. The best way to use such a method
is to top-rank all of your strong top-set, and not rank any of your strong
bottom-set.

...and, if there's a chicken-dilemma, then you can make use of that
rank-method's way of deterring chicken-dilemma defection...as the only
exception from voting as in Approval, by top-ranking your strong top-set.

That's really the only justification for a rank method.

But, for some electorates, maybe ours here, there's a _psychological_ need
for rankings. Some overcompromisers (as I said) would insist on approving
Hillary, along with Jill.

But some of those, if they had a rank-method, would be content to rank
Hillary a little below Jill. For them, the rank method improved their
voting. For that type of overcompromiser, a rank method softens their
voting errors.

Ranking can likewise soften the voting errors of rival parties who are so
inimical (though close in policy proposals) that they'd refuse to approve
eachother in Aproval.

So rankings can soften voting errors, for rivals and for some
overcompromisers.

...but not for all overcompromisers. Some overcompromisers are so
overcompromising that the only thing that can keep them from voting
Compromise over Favorite is if they have an opportunity to rank them both
at top, with the assurance that top-voting Favorite can't possibly hurt
Compromise. ....in other words, for them, the method must allow equal
top-voting, and must meet FBC.

So, what kind of method would meet the needs of both of those 2 kinds of
overcompromisers? It would be a method that allows equal top-voting, meets
FBC, but also allows ranking.   ...and preferably it should give good
protection of higher-ranked candidates against lower-ranked ones.

There are a number of good methods that have those attributes. Bucklin is
the familiar one, During the Progressive Era, Bucklin was used in at leasts
39 cities.

There are others too.

But I've only been talking about the _psychological_ need for ranking. But
I mentioned earlier that, disregarding that psychological need, there's
really only one genuine practical use for a rank-method: Avoiding chicken
dilemma.

Chicken dilemma protection is very costly in terms of problems that come
with it, to the detriment of other properties. ...especially to the
detriment of the method's general protection of higher middle-ranked
candidates against lower-ranked ones and unranked ones.

But, because the chicken dilemma is a genuine reason to use rankings, and
the only genuine reason, I'd prefer to have chicken dilemma protection,even
at the cost of general protection of middle-ranked candidates.

We've been discussing a few methods that meet FBC, have a way of avoiding
chicken dilemma, and give as good a general protection to mid-ranked
candidates as can be gotten in a method that meets FBC & avoids chicken
dilemma.

They're Simmons' method ( MDDA(pt/2) ), and MMPO(pt/2).

MMPO(pt/2)'s chicken dilemma deterrence is automatic, but its general
protection of middle-ranked candidates is uniformly questionable, chancy,
something of a crapshoot.

Simmons' method does a top job of that general protection for the
middle-ranked candidates against whom you aren't using the chicken-dilemma
defection-deterence measure (...which consists of denying them approval)..

With that, I'll conclude this note.

Michael Ossipoff








On Mon, Nov 21, 2016 at 1:08 AM, Daniel LaLiberte <
daniel.laliberte at gmail.com> wrote:

> This message is about two related subjects:
>
> 1. Factoring in the long-term emergent effects of each voting system.
> 2. An example of how Approval Voting results in better long-term effects.
>
> Among the many criteria for evaluating voting systems (
> https://en.wikipedia.org/wiki/Voting_system#Evaluating_
> voting_systems_using_criteria) I don't see any that address the long-term
> effects of using each voting system.  In other words, the effect on one
> election is certainly important, regarding the satisfaction of the election
> results by voters and candidates.  But I would argue that it is even more
> important to consider the long-term effects that emerge when applying a
> voting system repeatedly over many elections.  A small bias one way or
> another may not be very apparent if you only look at one election, but over
> may elections, they can add up and perhaps compound the bias exponentially.
>
> There are many long-term effects to consider, but in particular, I am
> thinking of one pernicious problem: the tendency for two major parties to
> emerge and dominate all politics which results from the repeated
> application of plurality voting.  This problem is fairly easy for most
> people to understand, although I am surprised to see that there seems to be
> a lot of denial about this effect as well.  Some would even defend having
> only two major parties, or very few parties.  That is an interesting
> subject to discuss, but regardless, I believe we should be aware of how our
> choice of a voting system will affect things over time, how society is
> likely to evolve based on the rules we lay down, and in fact, how it is
> actually very likely that the dominant forces in society will quickly and
> vociferously defend whatever rules resulted in their rise to dominance.
>
> But back to this one question, studies and long-term experience have shown
> that other voting systems besides plurality, in particular IRV, also result
> in the dominance of two major parties.  This may be more surprising to
> people, but looking at the underlying cause, it seems we can make a rather
> important simplifying argument about most voting systems regarding this
> problem. I would assert that the underlying cause of this problem of
> two-party dominance in any voting system is that it gives voters the
> ability to rank or order at least one candidate higher than the rest.
>
> The reason this ability to rank candidates becomes a problem is the
> spoiler effect, where voters will have a strong motivation to give their
> highest rank to one of the leading candidates. If they don't, then they
> weaken the chance of that candidate winning and therefore strengthen the
> chance of the less preferred leading candidate.  Because one of the leading
> candidates is likely to win, all the rest of the rankings of non-leading
> candidates hardly matter at all.
>
> In any election, there will be two candidates who are the strongest in
> terms of popular support, and thus the most likely to win. Consequently (to
> grossly over-simplify the process) with any voting system that permits
> ranking, groups of voters will tend to coalesce around support for these
> two leading candidates to encourage everyone to support their preferred
> leading candidate. Eventually two major parties arise, and everyone who
> doesn't join one of these two major parties is excluded.
>
> So once voters and candidates figure this out, any such voting system ends
> up devolving into the dominance of two major parties that we get with
> simple plurality voting.  In fact, one might argue that plurality voting is
> better just because it is simpler.
>
> But Approval Voting avoids this problem. Equal-rank approval votes mean
> voters don't get the option to express their preferred ranking, but because
> of that, they aren't at all motivated to bias their ranking dishonestly.
> They only have to decide which candidates to approve, or where the cut-off
> is between approval and disapproval.
>
> Given that there are, as before, two leading candidates, how does Approval
> Voting affect whether one of those two leading candidates will win?  One of
> the two leading candidates is likely to win even with Approval Voting, so
> it would appear there is no benefit, but that would be a short-sighted way
> to judge a voting system.  In subsequent elections, it would seem likely
> that more candidates will run who have broader appeal to ALL voters, not
> just a majority or plurality. Because the winning candidates will be those
> who are most approved of by the most voters, there will be no value in
> parties that typically focus on appealing to no more than half of the
> voters.
>
> So I suspect the long-term use of Approval Voting would be self-correcting
> toward better and better representation of ALL voters, not just half the
> voters, because in each election, almost all of the voters contribute to
> choosing the winning candidates, and that only gets better over time as the
> candidates who decide to run get closer to receiving the approval of all
> voters.
>
> Can any other voting system claim a similar long-term effect?  Even a
> voting system with three ranks, e.g. Approve, Neutral, Disapprove, would
> encourage voters to approve one of the leading candidates, and give neutral
> or disapprove votes to the rest.  I wonder if Approval Voting might be the
> ONLY system that has this long-term effect.
>
> What I am aiming for is a voting system that self-corrects over time.  No
> matter what voting system we choose, there is probably always going to be
> at least some small bias, some inequities or incompleteness.  So we need to
> understand this and deal with it.
>
> But one important question should not be overlooked: What do we want to
> self-correct toward? That is, what is the long-term goal? I believe we
> should want to move toward a closer or better representation of society as
> a whole, but there are other ways to look at that.
>
> Looking forward to reading your feedback.
>
> --
> Daniel LaLiberte
> daniel.laliberte at gmail.com
>
> ----
> Election-Methods mailing list - see http://electorama.com/em for list info
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.electorama.com/pipermail/election-methods-electorama.com/attachments/20161121/2ab5f0cc/attachment-0001.htm>