At 11:57 PM 4/24/2010, Kevin Venzke wrote:
Hi Abd,
--- En date de : Sam 24.4.10, Abd ul-Rahman
Lomax <[email protected]> a écrit :
> This is what is common with the
> use of voting systems criteria to study methods. Scenarios
> are created, sometimes cleverly, to cause a failure of a
> criterion. Does it matter if those conditions never exist?
> It should.
For the simple question of whether the criterion is satisfied or failed,
no it doesn't. Of course people then do go on to disagree about whether
certain criteria are important, and why. There is nobody who thinks every
single criterion is important.
That's right. But until utility analysis started
to be done, the arguments had practically no
foundation, they were just ideas about what
democracy should look like, sometimes intuitions,
and sometimes quite deceptive. Some criteria may
be positively harmful, and Later No Harm is one
of those. No method that maximizes utility can
satisfy Later No Harm, no method that finds the
best compromise winner can satisfy it.
And no method that maximizes social utility,
overall satisfaction, can satisfy the majority or
condorcet criteria, as fundamental as they seem,
when only a single ballot is used. They can by
using a second ballot to ratify (or reverse) an
original election that finds the utility maximizer.
I don't think mono-add-top is very important. Markus probably doesn't
either.
The design of the criterion neglects, like almost
all criteria, preference strength.
> And now we come to my objection to Woodall's "harm"
> criteria. The consideration is whether a vote "harms a
> candidate," not whether or not it harms the *election,*
> i.e., the *electorate.*
If it does harm a candidate then it also harms the voter who added the
preference.
Not necessarily. Suppose I have a favorite I rate
at 10. But there is another candidate who is
really almost as good, and, in fact, this
candidate I rate at 9 is better than I've every
experienced being elected. Am I harmed if my
lower ranked vote for the 9 causes the election
to complete for this candidate, whereas without
my vote perhaps it was a tie and it went to a
runoff between the 9 and the 10? And did my
adding that other vote actually "harm" my
candidate, or did it merely reduce my support for the candidate?
The goal of voting systems is to find a social
compromise, and to fulfill that goal the
favorites of many voters, sometimes even a
majority of voters, must be "harmed," if we think
not being elected is a harm.... Compromise is
essential to community decision-making, and it
always involves this kind of "harm." What a
Later-No-Harm method does is to protect the voter
from "harming" a candidate by taking the
candidate out in back and shooting him. And then
the method comes back to the voter and says, "Now
that it won't harm your candidate, may he rest in
peace, who else would you like to vote for?"
However, sauce for the good is sauce for the
gander. If the method hadn't taken my favorite
out back, if my favorite remained in the race,
the method can still come to me and say, "is
there anyone else acceptable to you?" And while
my answer might "hurt" my favorite, on the other
hand, the answers of others might "help" my
favorite. My answer only has the possibility of
"hurting" if my candidate wasn't going to win without additional votes.
Absolutely, if I answer "yes," this might result
in some other choice than my favorite. But what
would neighbors do, faced with a need to make
some collective decision. Stick to their favorite
until they absolutely know that, no matter what,
their favorite isn't going to win? Let's say that
I prefer not to have neighbors like that, and I'd
prefer not to be a neighbor like that, and I'm
unimpressed by a voting system that thinks this
is something good it can offer to me.
He could (depending on many factors, reasonably or
unreasonably) withhold lower preferences as a result, which means less
sincere voting.
No. This is a very common error. One withholds
lower preferences because the preference strength
is high. Truncation is not insincere, quite
likely. A good voting system solicits and rewards
sincere votes, and what we have done is to assume
that voters aren't sincere when they say, "I
prefer my favorite enough that I don't want to
take a chance of electing someone else, I'm
willing to take the risk that my vote becomes moot."
Usually sincere voting produces a better outcome, in
this case due to a greater amount of information provided. So ultimately
the good of the electorate is the consideration.
"Sincere voting" is unfortunately not well
defined, and so the statement that "sincere
voting" is better is problematic. I agree that
more information is better, but what kind of
information? If incommensurable statistics are
amalgamated, the result is noisy.
I've been working pretty intensively on Bucklin,
and I believe that a strategically optimal
Bucklin ballot, if Bucklin is used in a primary
-- I'm leaving aside for the moment of Bucklin
used as a deterministic runoff -- is a Range 4
ballot with sincere ratings based on the favorite
being a 4 and all candidates preferred to a
runoff being rated 2 or 3. This has to be
Bucklin-ER, of course. It gives the voter no
strategic advantage to vote this ballot
insincerely. If they prefer the runoff to every
candidate other than their favorite, *they prefer
the runoff*, and they might truncate entirely.
It's a sincere vote, and it is on a scale that
treats all voters the same, assuming that it is
equally valuable to them to avoid a runoff, as an absolute.
I believe that this method will discover if a
majority of voters are ready to settle on a
candidate. If they aren't, it will give them very
good information to use in determining how to
vote in a runoff. As a ranked ballot with four
ranks (including the bottom), Condorcet analysis
can be done, whether it is used for the election
or not. I've suggested adding an additional rank,
rating value 1, to be used to make the scale
symmetrical, these are not approvals of the
candidate, but they can be used to estimate overall utility.
To me, it's quite important to start collecting
much better ballot data, and this would do it,
with sincere votes incentivized. The ratings of 1
would not harm any approved candidate, they
merely would be a way for voters to make a
discrimination between the unapproved candidates.
They could be used to determine runoff candidates
(and with a good runoff method, it's possible for
there to be more than two runoff candidates, such
as the Approval Winner, the Range Winner, and a
Condorcet winner, if they differ (which would be rare)
Honestly I don't know how one could advocate a criterion which provides
a guarantee arbitrarily to candidates or voters without any greater
purpose. You have to be able to say that "people in general" receive a
benefit from this criterion (all things being equal, of course).
Kevin Venzke
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