[Election-Methods] RE : Re: RE : Re: RE : Re: RE : Re: Simple two candidate election

Kevin Venzke stepjak at yahoo.fr
Tue Dec 25 23:45:03 PST 2007


--- Abd ul-Rahman Lomax <abd at lomaxdesign.com> a écrit :
> At 09:47 AM 12/25/2007, Kevin Venzke wrote:
> > > [...] Range, voted with full strategic
> > > effect, reduces to Approval Voting, which may reduce to bullet
> > > voting. It *still* is not Plurality, because it only takes a few
> > > percent of voters adding multiple votes to eliminate the spoiler
> effect.
> >
> >So you say that if Range is not quite as bad as Plurality, then that's
> "as
> >well as hoped" for Range? I think most Range advocates have higher
> hopes.
> No. But I can understand why Mr. Venzke would think that's my 
> position.

Well, you appeared to disagree with my "summary in 25 words or less." I'm
only trying to figure out why you disagreed with it.

> When a writer writes something that, without careful 
> reading, can be interpreted to confirm some stereotype, it's very 
> easy to overlook contradictory details. Further, an extension of the 
> Wikipedia principle of Assume Good Faith, which is to assume that a 
> writer is actually saying something of interest, would require not 
> being satisfied with a shallow and meaningless interpretation.

If you can understand why I don't understand what you were saying, why are
you bringing up "Assume Good Faith"?

> Read what I wrote. I described what happens under certain conditions, 
> the *worst* case. And then I noted that a few voters voting other 
> than Plurality style are enough to solve the number one problem with 
> Plurality. That's not shabby, particularly for Approval, which 
> accomplishes this at no cost, merely starting to do what should have 
> been a no-brainer from the beginning. It's the elephant in the living 
> room, we never noticed, thought he was part of the furniture.

Alright then, so "as good as hoped" is Approval? It seems to me "as good as
hoped" involves many voters not exaggerating their preferences. You don't
agree with that? Do you say that Range advocates generally set their sights
lower for Range?

> I did a study of strategic voting in Range 3, using some simple 
> assumptions: three candidates, many voters, utilities for the voter 
> of 1.0, 0.5, 0, and zero knowledge. Turns out that the sincere vote 
> utility is equal to the "strategic vote" utility in that case, which 
> is the same whether the voter votes (1,0,0), or (1,1,0). The claim 
> that bullet voting is higher utility is not correct, it depends. 
> *Accurate* sincere voting is on a par, at least, with "strategic 
> voting," but there were different implications. The exaggerated vote 
> resulted, as one might predict, in more wins for the favorite. But it 
> also resulted in more wins for the least-favored. The sincere vote 
> was less variable in result.

This is (virtually?) always true when a candidate's value equals the
expectation from the election.

> There was another interesting result from that study: if we take the 
> Range election, with equal expected outcome for both the sincere vote 
> and the strategic vote, and make it an Approval election, i.e., 
> restrict the set of legal votes to the Approval style votes, the 
> expected outcome *declines.* The existence of even one voter who 
> votes intermediate causes the entire vote distribution to dither, 
> increasing accuracy, at least that's my theory of why this occurred.
> (More study is needed to confirm this; Warren Smith did co-author a 
> page on it at rangevoting.org, so I think the math is sound; but the 
> implications of converting to pure Approval have not been confirmed.)
> However, first things first. While Range may be theoretically 
> superior, Approval does improve results quite a bit in the 
> simulations, and it is blatantly obvious why. Approval is free, just 
> Count All the Votes. In the ranked form, Bucklin, it was used fairly 
> widely in the U.S. at one time, though before the living memory of 
> nearly everyone.
> Consider this an election, and electability is important. The 
> candidates are Plurality, IRV, Approval, Range, Condorcet. How would 
> we vote in this election, held right now, assuming some level of 
> public education in the campaign? How should the election be held? 
> What method should be used?

So, I have no information about other voters' preferences? I would prefer
Condorcet. Although my best Range vote involves a strict ranking, that
doesn't mean other voters find themselves in the same situation. I could
certainly hope for a better (or worse) outcome under a different method.

> >Your claim that strategic Range voters are actually sincere is not
> >different from choosing to believe that the Plurality winner is always
> the
> >favorite candidate of the most voters.
> I'm disappointed. Mr. Venzke, I've seen much better analysis from 
> you. Look again.
> In Range, there is no strategic advantage, ever, to reverse expressed 
> preference from real preference. 

I don't think it matters. Why can't I argue that the Nader supporter (who
should understand how "sincere" Plurality is to be voted) who votes for
Gore is actually voting for his favorite? Surely if his favorite were
really Nader then he would vote for him?

> The so-called "insincere" vote in 
> Range is simply a non-linear squeeze of the internal utilities, or 
> another way to put it, the internal absolute utilities are 
> normalized, first -- nearly everyone will do that, since an election 
> is a choice, and choices are almost automatically normalized -- then 
> the scale is expanded depending on two factors: expectations of how 
> the electorate as a whole is likely to vote, and the effort the voter 
> is willing to put into determining how to vote. Approval-style voting 
> is relatively easy, and a lot of voters are going to do just that.
> In Plurality, by contrast, strategic voting requires preference 
> reversal, as with all ranked methods where equal ranking is not allowed.
> It's simpler to see with Approval. I claim that a sincere vote in 
> Approval is a vote which divides candidates into two sets: Approved 
> and Not Approved. There is no reason for a voter to insincerely vote 
> (other than through misunderstanding the implications, and they are 
> pretty simple); an insincere vote would be voting for a candidate 
> when another candidate preferred over him or her does not get a vote.

Well, I would say that a sincere Approval vote probably should be defined,
by you, in the same terms as a sincere Range vote. There is no difference
between them except the number of slots.

If you say that a sincere Approval vote would always also be a sincere
Range vote, then that does shoot down my criticism. But it also means that
when you argue that exaggerated Range votes are actually sincere, it's
almost a tautology, and doesn't require you to make any argument about
exaggerating voters really truly desiring things to be as they vote.

What I have always taken you to be arguing is that when a Range voter
desires to vote Approval-style instead of "Range-style" (using middle
ratings), this is no less sincere than if with the same preferences he
chose to vote Range-style and not exaggerate. That is what I don't agree
with: Since there is no incentive to vote "Range-style" other than to "play
nice" and do what CRV hopes (this is what I meant by the "suggestion" of
how to vote), you can't learn anything from the fact that a voter chooses
to exaggerate his ratings.

Example: If I instruct you not to eat ice cream tomorrow unless you are a
communist, and then I find out that you actually did eat ice cream, should
I conclude that you're saying you're a communist? I guess I should conclude
that you just didn't care what instructions I give you, and had more
important things on your mind.

> Range instruction (Range 3, +/-): For each candidate, mark Yes or No 
> or leave the boxes blank. The candidate with the highest result, 
> after No votes are subtracted from Yes votes, will win. A blank vote 
> will not affect the total. (This is Range 3, the three possible votes 
> are -1, 0, +1; the default vote pulls the average toward the center. 
> However, it is also possible that there would be an explicit zero, 
> and that average result would be used. I don't care to debate this, 
> at this time, there is plenty of time. If we can't get Approval, 
> Range is really pie in the sky.)

If these were the only guidelines Range advocates had in mind, there would
be no need to discuss whether strategic Range votes are really sincere,
because it's not even clear from this how to define a "sincere" vote.

Clearly the ballot paper should have instructions in this format, but for
analysis purposes I believe Range advocates are not agnostic as to what it
means to use intermediate ratings.

Kevin Venzke

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