At 09:22 AM 7/1/2013, David L Wetzell wrote:
Some thoughts.
1. You need to consider the difference between Cardinal and Ordinal Utility.
You presume the existence of Cardinal utility.
First of all, who is "you." David is writing to an entire list. *Who*
"presumes"?
In the study of Bayesian Regret, we do *not* presume the existence of
cardinal utility, we *assume it.* It's a device for studying voting
systems, to see how they perform when we know *summable cardinal utilities.*
Ordinal utility can be monotonically positively transformed so
long as it preserves the order. For example, if the original scale
is between 0 and 100 then one could randomly generate a real number
a from the normal distribution, transform it by taking b=E^a, and
then transform the utility to become X^b *100^(1-b). This would
not change the rank-orderings of candidates, but it would change
the approval or score-ratings given to candidates and it'd muddy
the water about your example.
Well, we aren't looking at the example. However, there is a radical
misunderstanding of how cardinal utilities are used in studies. The
choice of representational range is a study option, and it's
arbitrary. Utilities may be represented in the range of 0 to 1, or
using any real number, positive or negative. What matters is the
assumption: these are *absolute* utilities and the scale is *assumed*
to be commensurable. Often "heaveh-hell" utilities are used. These
represent *actual motivational* preference. I.e, assumed. The
absolute utilities that underly a study assume commensurability, and
incommensurable utilities would be adjusted so that they are commensurable.
This system makes a basic assumption that all voters are equal,
equally deserve to be pleased. So the *full range* of pain/pleasure
for these voters is made equal.
The utilities in the example that David is referring to seem to have
been utilities on a scale, perhaps, of 0 to 100. These are utilities
that have been transformed to representation on a scale of 0 to 100.
They are no longer absolute utilities in the sense described, but we
can still posit such utilities, for simplicity, and see how a voting
system performs.
Take-home point: we are not "presuming" commensurable utilities, we
are "assuming" them for purposes of study. David is falling into a
classic error, *presuming* that to be useful, utility must be real.
What we are doing when we assume a set of utilities is saying that
*if there are utilities like this,* then this result is better than that.
Something else is done. If the value stated is *actual range votes,*
then those will have been translated through voter strategy. They can
no longer be assumed to represent commensurable utilies. Without
knowing the example used, and how it was used, I can't know what was
being discussed.
2. In real life, parties/candidates choose their
candidates/positions to enhance their likeability, so what is taken
as exogenous in most of our thought experiments are in fact
endogenous. This is also another reason why it's hard to grow the
number of competitive candidates, because good ideas from a
not-so-competitive candidate will tend to get coopted by
already-competitive candidates.
David is taking a *very simple situation* and making it quite complex
and difficult-to-understand. He's just making up a story about what
happens, which might have some effect, and it might not. He is
aiming, it appears, to make some claim about the numbers of
candidates, claiming that it is "hard to grow" them, when we don't
give a fig about "growing the number of candidates." It will happen,
that's what we know. It's like clockwork, under some election
conditions. People like to run for office, and it's commonly easy to
get on the ballot in nonpartisan elections. David is mixing up
partisan and nonpartisan elections, smearing it all together as if
they were the same.
Presently in many places we see minor candidates, and minor party
candidates, with few votes. They do this in spite of the spoiler
effect and vote-splitting. Top two runoff, in some places, causes
massive spawning of candidates/parties. It's obvious. IRV will do the
same, and so will any method that addresses the minor spoiler effect.
The major effect is vote-splitting, which becomes a serious problem
for IRV as a minor party approachs or just exceeds parity. Since IRV
will encourage the growth of minor parties, that can be predicted --
and it would happen with other systems as well -- we can see, then,
that IRV is likely to eventually create the conditions for its own failure.
FairVote, had they been capable of intelligent strategic thinking,
would *never* have chosen Burlington as a place for IRV. Bad Idea.
But Terry Bouricius was there, and they had LWV Vermont in their
pockets. They were screaming when the move was being made to drop
IRV. Quite simply, they were not listening. They had stuffed their
fingers in their ears, they were not going to recognize a problem
with their baby.
3. It seems that your self-described magical certainty as to voter
prefs is at worse chimerical and at best a useful fiction.
Again, this is that basic analytical error. David is not
understanding what he sees. He is seeing an "assumption" of voter
preferences, i,e., of underlying utilities -- which then define and
create preferences and preference strengths. It is not a "magical
certainty," it is an assumed condition. It is not intended to be an
actual representation of real-world utilites, merely as a possible
pattern. Unless it was. If this was properly done, for that, the
assumption would, again, be explicitly stated.
It also is similar to the work by Warren Smith using
<https://www.google.com/webhp?sourceid=chrome-instant&ion=1&ie=UTF-8#sclient=psy-ab&q=warren+smith+bayesian+regret&oq=warren+smith+bayesian+regret&gs_l=hp.3..0i22i30.102.153444.0.153747.35.30.0.0.0.1.365.5918.0j20j8j2.30.0.epsugrpqhmsignedin%2Chtma%3D120%2Chtmb%3D120..0.0.0..1.1.17.psy-ab.FsjX8OuCjSc&pbx=1&bav=on.2,or.r_cp.r_qf.&bvm=bv.48572450,d.aWc&fp=e16824eab702e431&ion=1&biw=1366&bih=659>Bayesian
Regret, which also presumes cardinality of utilities.
No, it *assumes* this. Arrow made this error years ago, but he
clearly moved beyond it. Simulated commensurable utilities are used
to test the performance of voting systems with known utilities. The
real assumption, involved in our thinking that these studies have
real application, is that a voting system will then perform similarly
with unknown utilities.
If a voting system can't perform well with clearly commensurable
utilities (such as payoff values in some lottery or cash benefits,
etc.) then why would we expect it to perform well when we don't know these?
It's important, of course, to be very careful about how simulated
utilities are translated to actual votes. Again, that's all invented.
Is it realistic? We debate about that. But Bayesian Regret
simulations are the only relatively objective tool we have to study
voting system performance. There are also, in a similar fashion, Yee
diagrams. It is obvious why IRV supporters attack the simulations:
they show how bad IRV really is.
We knew from simulations that what happened in Burlington was a real
possibility. FairVote denied it, claimed that the scenarios that
would lead to monotonicity failure and the like were terminally rare
and therefore irrelevant. And so it actually happened, as could have
been predicted. There was nothing magical about it.
The assumption of commensurability is fundamental to democracy, it's
behind the one-person, one-vote principle, that values the
contribution of each voter equally.
I think that there might be scope for probabilistic valuing of
candidates so that in examples like what you give, a certain
candidate has a certain probability of getting elected.
That can all be incorporated into simulations. Better study of
strategic voting in Range and other methods has yet to be done, the
work so far has been primitive.
[...]
4. If there is a multi-dimensional issue-space (plus a
je-ne-sais-quois character dimension) then these inevitably would
tend to get collapsed into a single-dimension and the issue is in
large part how the different dimensions get collapsed, plus the
inevitable problems with noise being propagated by the campaigns and
voters putting less time/energy into researching all candidates so
and so forth.
It can all be simulated. However, the point is not to accurately
simulate real elections, but to simply come up with some reasonable
distributions of preferences and voting strategy. It doesn't have to
be complex to work.
I favor IRV in part because it lets non-competitive candidates
bring up otherwise neglected issues and subvert some of the noise
spewed by the main candidates.
Any advanced voting system will accomplish what is real about this.
Much of the prediction about how IRV will, for example, stop negative
campaigning, is just made up. It does not appear to correspond with
reality. So two relatively compatible candidates, minor candidates,
campaign together. That's happened, but it isn't common. And the
major negative campaigning comes from frontrunners. They don't attack
the minor candidates whose supporters they might want to woo, they
attack the other frontrunner.
These are things that are hard to model, they are quite indeterministic.
David, you are presuming there is a need to model real behavior. You
are using this to deny a presented model, an example, I'm assuming,
of method behavior, given certain assumptions. Sometimes I address
these by looking at what utilities might underlie give voting
patterns in examples. Sometimes I assert that a scenario is extremely
unlikely or even that it is self-contradictory. However, here, David,
you are attempting to undermine the entire approach of using assumed
utilities to study voting system performance.
It's a head-in-the-sand approach.
The same is likely true for other rules, but their probabilities
of getting adopted in the short-run are low and my args are geared
not at proving IRV is objectively better than the other rules, just
that the diffs between the alternatives are less strong than often
purported and so it makes more sense to focus on short-term
probabilities of adoption in the short-run at least.
I prefer the continuation of plurality to the adoption of IRV. I
would *not* oppose STV multiwinner implementations, I expect. Why do
I prefer plurality? Because Plurality is honest. It's obvious what is
happening. Voters know the ropes, they know that by voting for Nader,
they might allow Bush to win. Nobody is surprised by that. But IRV
Republicans in Burlington, did they know that by voting sincerely for
the Republican, they were effectively causing the Progressive to win?
Their worst choice?
When this became clear, I assume, there was then a natural alliance
between the Democrats and the Republicans, to defeat the Progressive.
That's why IRV was dumped. The Republicans were more hurt than the
Democrats, but the Democrats, had the method been fair, would have
won that election, so they were also hurt. More than half the
electorate, up to about two-thirds, got a poor result. Roughly
one-third got the worst result, and another third, roughly, got a
poor result. Anyone who thought the Progressive was the best result
would have voted for the Progressive, which I'm stating at roughly
one-third. The Democrat was the compromise candidate, lesser in
direct support than the Progressive and Republican, but pretty much
the first or second choice of everyone. IRV -- like top two runoff --
is famous for this problem.
5. If some people feel strongly on an issue, there are other ways to
manifest this preference other than what is given them in the ballot
that serve to move swing/low-info voters. This reduces the mandate
to incorporate the capability to express strength of preference in the ballot.
This means something? Mandate? Looks like David is here dissing the
expression of preference strength, which is what differentiates
cardinal methods from ordinal methods. But any sane interpersonal
negotiation system will investigate, in one way or another,
preference strength. You and I disagree. Okay, *how strongly* and on
what specific issues? Maybe I can give some weak preference on
*this*, where you have a strong preference, whereas you give up
similarly on this *other* issue.
People socialized to cooperate and collaborate readily disclose
preference strength. People socialized to get as much as possible for
themselves, who fear that if others know their preference strengths,
may want to conceal them unless *forced* to reveal them.
Later-no-harm criterion.
This is not unlike why I stated that I have epistemic diffs with
Kristofer M. He doesn't have access to much real world experimental
data and so to compensate
I'm seeing only noise brought in from that "real world experimental
data." He means that he's more experienced, without actually having
"data." Just his collection of judgments and opinions.
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