[EM] RE : Re: A few concluding points about SFC, CC, method choice, etc.

[Abd ul-Rahman Lomax]

At 06:15 PM 2/16/2007, Kevin Venzke wrote:
>Hm? "Maximum utility" meaning "matches the SU winner perfectly" or
>"matches the SU winner the best among methods that actually exist"?
>
>In the former case it's not clear this method actually exists. In the
>latter case I'd guess that you shouldn't guarantee this.

Election criteria sometimes presume omniscience. For example, the 
Majority Criterion is based upon voter preferences that may not be 
expressed, or even expressable, in the votes. "Prefer," as it was 
clearly interpreted here, refers to a mental state of the voter.....

So we can state that if a method elects the candidate who maximizes 
voter expected utility, summed across the electorate, it satisfies 
the Expected Utility Criterion. And we know, without doubt, that the 
Expected Utility Criterion and the Majority Criterion are not 
mutually compatible.

What we are limited to, however, is what voters actually express. 
Condorcet methods purport to elect the pairwise preference winner. 
But if voters vote "strategically," that is, they don't express their 
actual preferences, the method can fail to select the actual preference winner.

Range, of sufficient resolution, *is* precisely a method which 
explicitly selects the utility winner, if voters vote sincere 
utilities. So Range satisfies the EUC. Got any other methods which do this?

If voters don't vote strategically, then it can fail to find the 
utility winner. Garbage in, garbage out.

But the real practical question is whether or not it fails 
gracefully. And it appears that it does.

(There are other limitations. Range, for example, equates all voters. 
This assumption certainly causes a mismatch between results and true 
utility, but the assumption appears necessary in a democracy.)


> > Yes, the statement is true, but it is completely off the point. We
> > are not comparing "arbitrary methods."
>
>It's not off the point. It's a response to this comment of yours:
>
>"Too often, when we consider methods by election criteria, we assume that
>a criterion is desirable, entirely apart from whether or not it chooses
>the optimum winner."
>
>This makes it sound like you don't understand why criteria are used or
>think that they are inherently at odds with SU. That's why I replied in
>the way I did.

It makes it sound like that because, which I wouldn't say "inherently 
at odds with SU," I *would* say that Election Criteria, most of them, 
are indirect. That is, we presume that it benefits society for the 
Majority Criterion to be followed. But, in fact, this may not be the 
case. More accurately, it is true only under certain conditions.

It's indirect. Instead of saying that we want a red shirt, we say 
that we want a shirt that gets a bull excited. That might get us a 
red shirt, but it might not.

For me, the only question about SU is the best way to measure it. The 
Condorcet Criterion has *nothing* to do with measuring SU. It's just 
a guess at a beneficial method, an intuititively satisfying one that 
turns out to miss something extremely important.

> > It is obvious that MF has a utility. It is unlikely to choose a truly
> > bad candidate.

It can and has, so I don't know about "unlikely." Think Ruanda. (Now, 
I don't know the full details of the election involved, but it was 
won by the leader of the majority Hutu tribe. I'm guessing that he 
was a majority victor.)

>  But methods which specifically optimize utility are
> > going to fail MF. That's the point.
>
>As far as I'm aware, there is no way at this point to conclude that there
>is a method failing MF that optimizes utility better than every method
>that satisfies MF. Or vice versa for that matter.


>If you want to posit sincerity, though, then never mind this comment.

There is no real alternative to positing sincerity. *No* method can 
guarantee good results if the voters don't disclose their opinions!

Yes, it's possible to facilitate this. What is completely obvious to 
me, though, is that ballots which only collect preference information 
are inadequate, because preference strength is essential information 
for the maximization of utility. Many elections, to be sure, will 
have a range of candidates such that preference strength is not 
important. And this is the reason why Plurality works as well as it 
has, and why Condorcet methods would work as well as we can expect.


> > I've argued that the majority has the right of decision. In this
> > example, if the majority wants to ensure the election of A so much
> > that it is willing to damage society, overall, it may do so. It
> > simply votes B at a lower rating, sufficiently low that B loses. But,
> > and I've given this argument again and again, this willingness
> > conflicts with an assumption: that the majority values B at 80.
> >
> > No, if they are willing to lower B's rating to very low, which is
> > what it would take, it is necessarily true that they place a higher
> > relative value on the election of A than the supposedly sincere
> > ratings indicate.
> >
> > There is a conflict in the assumptions, if we think that the A voters
> > will vote insincerely. There has to be a motive to vote insincerely,
> > a gain expected, and the gain cannot be trivial. Most people, in my
> > opinion, won't lie on a matter of importance for trivial gain (and
> > especially when their vote is anonymous).
>
>I commented on this idea some time ago. I think I would find it more
>interesting and convincing if you (or someone) would propose some
>formulas, so that we can determine how to transform sincere ratings into
>ratings that take into account the voter's willingness to take full
>advantage of the method.
>
>Otherwise it is not obvious how, or if, you can compare preference
>strength to the voter's likelihood of being strategic.
>
> > If you really think B is quite good -- and 80% is quite good -- then
> > why would you rate B at zero, merely in order to get a slight
> > improvement in personal utility, while at the same time knowing that
> > you are going to be seriously disappointing half the society?
>
>If you're saying that
>1. electing A seriously disappoints half of society, and
>2. I do not want to seriously disappoint half of society
>
>Then I don't see how it can possibly be that I rate A higher than B.

Yes. However, that is post-facto information. How would I know that I 
will seriously disappoint half of society? *The poll is the 
information.* I have argued again and again that single-step election 
methods are doomed to be inferior to more complex, essentially 
deliberative, process.

But we are considering methods which are *required* -- with, perhaps, 
some runoff provisions -- to complete in a single poll. Some writers 
seem to assume that real runoffs are a waste. And top-two runoffs 
suffer from the same problem as IRV, the center-squeeze effect. 
However, a complete poll that does *not* generate a winner but merely 
informs the electorate as to the range and strength of opinions in 
the electorate would be necessary to have the information that would 
cause me not to "rate A higher than B."

Here is a way in which a Range method satisfies the Majority 
Criterion: A Range poll is taken and the winner is presented for a 
second vote to the electorate, "Shall the Range Winner be elected?"

If the majority votes Yes, we have, with the overall method, 
satisfied the Majority Criterion.

We could also do the same thing by presenting the Range Winner 
together with the best winner by any other method, in which case, the 
question would be a runoff between two candidates.

While methods, in my opinion, should optimize utility, the majority 
should retain the right of decision. I'm claiming only that the 
majority should be informed when it makes that decision.


> > This is a basic question, a different view of human nature than is
> > being expressed by some. Are people generally out only for
> > themselves? Will they impoverish their neighbors for a small gain?
> >
> > We know that people can be selfish. But *how* selfish? If you
> > discover that burning your neighbor's house down, and you are sure
> > you can get away with it, will somehow raise your own property value
> > by a few thousand dollars, would you do it? How would most people
> > answer this question, and how would they act if actually faced with
> > the situation.
>
>The answer to the house-burning question is that it doesn't matter,
>because we can set up laws and institutions to handle the case that
>people do think it is worth burning each other's houses down.

The question is about human nature, not about how to prevent houses 
being burned down.