[EM] Approval vs rank methods
nkklrp at hotmail.com
Thu Nov 10 21:59:06 PST 2005
[replying to my Approval handtool analogy]
Tools vary in their abilities:
Plurality is excellent if approving of a single candidate is all I
Approval fills a gap - I can approve, equally, of one or more
Sometimes I want more than either of them is capable of, and desire a
more capable tool. Caring not where you divide tools between handtools and
...but you want something whose input is all of the voter's pairwise
preferences. And presumably something that makes good use of those pairwise
preferences, by some important standard. That requires a device, an
automatic machine. That's what you're saying you want.
When you collect that information, you either have a good automatic
majority-enforcement machine, or you have a shabby piece of shit like IRV.
Rank methods are majority-enforcing machines. A machine can be well-designed
and high-quality, or it can be a cheap and defective machine like IRV.
While we can agree on wanting better than IRV, since we know better is
available, does IRV deserve your nasty words?
I wouldn't say it otherwise.
Easy enough to describe a possible ugly failure, but how often might such
happen in real elections?
Well, someone said that it would have happened in Debian's most recent
election, if they'd been using IRV instead of Condorcet(wv).
Say there are 3 candidates, on a 1-dimensional political spectrum, with one
between the other two. The middle candiate is a CW if the 1st choice
popularity of all 3 candidates varies by no more than a factor of two.
That's a sufficient but not necessary condition. All it takes is for Middle
to be bigger than the difference between Favorite and Worst.
And then, when that's so, when Middle is CW, what is the probability that
Middle will be eliminated first, if we have no information about their
relative popularity? The probability is 1/3.
And even if the middle CW is favorite of more voters than any other
candidate is, that CW is sure to lose if favoriteness-strength tapers at all
gradually away from the median point. That's not a contrived scenario.
Then, the low-popularity candidates at the extremes will be eliminated
first, ane their votes will transfer inward, till candidates other than the
middle CW build up accumulated vote totals that eliminate the CW.
Several of us have posted such examples to this mailing list.
So, to answer your question, IRV's problem will happen a lot.
If the voters are as incompetent as they seem to show that they are, they're
going to need a good majority-enforcing machine so that they won't have to
incompetently make the all-or-nothing strategic decisions that the handtool
Approval would require of them.
While we can debate how much the voters might bother to learn, when they
have no opportunity to use such knowledge, should we assume that none would
learn if and when it started to make a real difference?
Not with certainty, no. As I said, the voters haven't been tried with
Approval, and no one can say for sure if they'd be unable to stop voting for
corrupt lesser-evil sleaze if their favorite outpolled their greater-evil.
But what I've been saying is that the voters' behavior so far doesn't
justify a lot of confidence in their competence.
Also, how can I learn to use Approval to rank candidates according the
acceptable vs only-tolerable qualities they display.
You can't rank candidates in 3 tiers (acceptable, only-tolerable, and
intolerably unacceptable) with Approval. I didn't mean to give the
impression that the voters are incompetent because they don't know how to
rank candidates in 3 tiers with Approval.
It's the other way around: Because they're incompetent, it's probably better
if they don't have to make the choices that Approval demands of them, the
choice of which of their pairwise preferences to vote.
Approval does not let competent voters vote their decisions full strength.
Corrrect: Approval doesn't _let_ people vote pairwise preferences full
strength: It _forces_ them to.
Do you use this refusal to see what is written when you debate with Markus?
You need to be a little clearer about what you mean.
I said that Approval forces people vote full-strength, all-or-nothing
preferences. It does. It doesn't allow them to. It forces them to. I stand
by that statement.
You say I didn't notice what you wrote. No, it's that you didn't write what
you meant. You said that
Approval doesn't let people vote their decisions full strength. On the
contrary, every pairwise preference that someone votes in Approval is
full-strength, in the strongest all-or-nothing sense. Full-strength in the
exaggerated sense of top vs bottom.
What you meant was that Approval doesn't let people vote all of their
pairwise preferences. I didn't reply to that (in that sentence), because you
didn't say it. Later, however, I replied to that, because I assumed that it
was what you meant. No, Approval doesn't let them vote all their pairwise
preferences. Just the important ones. And, unlike IRV, Approval counts every
pairwise preference that you choose to vote.
It only wastes everyone's time.
You mean like debating soimething that we don't disagree on? I, too, prefer
(the best) rank methods for public elections. We don't disagree on that.
You speak of wasting time. We've gone over the same ground a few times.
As for Markus, can you name an instance in which I disregarded what he said,
except when I finally got tired of replying to his parrot-like repetition of
Approval, which I also call Set Voting, lets you vote one candidate-set over
another. That lets you vote the pairwise preferences that really matter.
Anything more would be a frivolous luxury--except that, as I said, our
public election voters need that luxury.
It would be a luxury if the cost exceeded the expectable benefits.
No, then it would be a prohibitively costly luxury. But it can be a
frivolous or unnecessary luxury without being a prohibitively costly luxury.
Most of us seem agreed that rank falls on the affordable side of luxury.
Don't be so sure. I'd say that a lot of us hope that a good rank method can
be enacted. Some of us have talked about why that could be a problem: There
are innumerable ways to count rank ballots. We'd have to show people that
our proposed way is the best, or at least that it's good enough to go ahead
with enactment, without (never-ending) studies being conducted, though there
are infinitely many other ways to count rank ballots. We'd have to wade into
the bog of showing why IRV is crap, and why our proposal is better than IRV.
In contradistinction, there's only one way to count Approval ballots or RV
ratings: Add them up. RV wins the prize for familiarity and popularilty. RV
is the best bet for a public proposal.
I, too, would hope that the best rank methods, MDDA, MDDB,
MDD,ER-Bucklin(whole), and MAMPO, would be accepted and enacted. Maybe the
enactment of a good rank method is too much to hope for. But of course if
people are willing to bounce back with a backup proposal, then it wouldn't
hurt to try a good rank method before trying RV or Approval.
The debates over rank method details sometimes get a bit deep, depending on
plotters knowing unknowable details and having unbelievable control.
Maybe sometimes, but not when I write about it. No, the problem that I write
about is when the voter _doesn't_ know what s/he needs to know, and decides
to play it safe by voting Lesser-Evil over Favorite.
Again, IRV counts most [pairwise preferences], and its backers claim it
Its backers are full of shit. How consoling is it for you if IRV counts many
or most people's preferences but ignores a crucial pairwise preference of
Exactly. And the incompetents that I've referred to don't do a good job of
choosing which of those pairwise preferences to vote. That's why I want them
to be able to vote all their pairwise prefences, and have them all counted,
by a method with majority-enforcing criterion compliances.
I was not talking of voter incompetence
Of course not. I was talking of incompetence.
, for Approval restricts their possible actions.
As I clarified above, I'm not saying that the voters are incompetent because
they don't know how to vote 3-tiered preferences in Approval.
It's the other way around: It's because they're incompetent that they need
an automatic majority-enforcing machine that uses all of their pairwise
preferences, rather than a hand-tool that requires them to choose which of
their pairwise preferences to vote.
Still, I would not claim Approval incompetence, assuming it behaves as
I never said that Approval was incompetent, or questioned your competence to
What is left is designer incompetence, for not letting voters express their
You're saying that Weber and Ottewell are incompetent because they didn't
design a method that will work well for idiots? Blame the idiots, not the
Approval is a beautifully elegant method, and it's only because of questions
about voter-competence that I don't call Approval an excellent choice for
today's public elections.
You sound like someone complaining that Harley-Davidson was incompetent
because it designed and sold to you a motorcycle that didn't have
Yes, sincere rating is more work. But no one forces you to do that work. You
can just give maximum points to the candidates you'd vote for in Approval,
and give minumum points to the others. That's your best strategy. And
another reason to use that Approval strategy is that Approval is easier to
If this is your recommendation as to how voters should act with RV
Yes it is. (If that's what I said).
Yes, if you complain, as you just had done, that voting in RV is a lot of
work, then I recommend voting RV as if it were Approval, to make the job
..., why should it bother to exist?
1. Because it's much more familiar and popular than Approval or any rank
2. Because it likely will give somewhat better results than Approval in
today's public elections.
3. Because some might want to use RV's ratings to vote sincerely.
4. Because, like Approval and the best rank methods, but unlike IRV, RV
5. Because, unlike IRV, RV meets WDSC, in addition to FBC.
I disagree there: RV doesn't give any problem to counters. They merely have
to add up each candidate's points, and declare as winner the one with the
Ok, so the counters do not try to guess
Correct. They don't.
..., leaving the whole communications headache on the voters' weak
Take the difficult choices off the voters' weak shoulders by using MDDA,
MDD, ER-Bucklin(whole) or MAMPO instead of Approval or RV.
[with rank methods] Voters can indicate order of their preferences.
A necessity for our incompetent voters. Otherwise a frivolous luxury. As I
said, Set Voting (That's Approval) lets you vote one candidate-set over
another. Those are the important pairwise preferences, and that should be
Proper topic is whether capable voters are allowed to express their
Answer: Yes. With Approval, capable voters are allowed to express their
important preferences. Incompetent voteres are allowed to likewise, but, for
them, that doesn't help much.
But no, with Approvla, capable voters (and, worse, not-so-capable ones)
aren't allowed to vote all of their pairwise preferences.
..., not whether some voters may be incapable of better thinking - for which
more adequate education may be practical.
I disagree again: The capabiliies of the vulgar masses is something that
affects voting outcomes.
Education? Maybe honest &/or democratic media. Failing that, the best voting
system we can enact would do a lot of good. Some are workig to improve
media. Here we're talking about the benefit of a better voting system.
Counters can read these preferences in the same language as the voters used
That's true with Approval and RV too. And I remind you that Approval and RV
receive information that rank methods don't receive: Preference strength. In
that regard, Approval and RV are more expressive than rank methods.
You lose me here. You have suggested above ZERO ability to express
preference strength with Approval
Would you please quote the sentence in which I said that, and tell the date
of the EM posting that contained that statement?
- only two sets with zero preference within a set, and uncontrollable
maximum strength between sets.
As I said, Approval measures the strength of your pairwise preferences,
because you vote the ones that are most important.
Agreed you say voters can express strength in RV and that counters have no
responsibility for understanding there - leaving how voters determine what
to say a puzzle.
Let's avoid giving voters that puzzle by enacting MDDA, MDDB,
MDD,ER-Bucklin(whole) or MAMPO instead of Approval or RV.
But, as a practical matter, RV is a lot more gettable, and, despite the fact
that Approval and RV don't help incompetent votes as much as we'd like, RV
may be what we can get.
You think that Approval doesn't allow you to express as much because it
doesn't let you indicate the direction of all your pairwise preferences. But
Approval lets you express their strength: You vote a preference if it's
important enough to you. Rank methods let you express the direction of all
your preferences, but that's all. They don't let you express the strength of
No one denies that the best rank methods do the best job of enforcing
majority rule. But who says that's all that matters?
Agreed there are so many possibilities, and some offer so little value for
what they offer as to deserve "luxury" as a descriptor
I disagree again. If a method doesn't offer anything of value, there's
nothing luxurious about that.
, and some are so weak as to voters being able to express their thoughts as
to be useless, that we need more careful thought.
Other than Plurality, all the methods are good at letting voters express
preferences. For today's public election voters, the luxury of being allowed
to vote all their preferences might be a necessity.
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