[EM] Participation

[Kevin Venzke]

Hi Abd,

--- En date de : Dim 25.4.10, Abd ul-Rahman Lomax <abd at lomaxdesign.com> a écrit :
> > --- En date de : Sam 24.4.10, Abd ul-Rahman Lomax
> <abd at lomaxdesign.com>
> 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.

I don't understand your terminology. Does "maximize utility" mean pick
the best winner every time, or does it just mean the method that comes
closest to doing this on average? Either way isn't it just *one* method?
I could believe that that method doesn't satisfy LNHarm, but it would be
hard to demonstrate that that method was the big winner.

> 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.

When we analyze methods we will usually assume that voters don't change
their positions between rounds, and the same voters vote in both rounds.
It's hard for me to imagine what approach could be used to show the
utility advantage of multiple rounds.

> > 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.

I don't consider mono-add-top important because I don't think it would
deter voting, or could be abused, or would be politically inexcusable
if failed.

> > > 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?

Unless you want to invent new terminology, then yes, you are "harmed"
when your 9 vote moves the win from the 10 candidate to the 9 candidate.
I don't know what the practical difference is between "harming" your
10 candidate and "reducing your support thereby making him lose."

The reason we expect that to be bad is that if next time you choose
not to rank the 9 candidate, you could let your 0 candidate win, which
isn't what we want because we (the scenario designers) know that you
actually did have a compromise choice.

I guess your response would be "maybe the 9 candidate sucked." Maybe,
but we don't know, and I tend to think that in general, compromise
choices provide better utility than flank candidates.

> 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?"

That's IRV. Most of the LNHarm methods don't eliminate candidates, the
particularly interesting ones being DSC and MMPO. (DSC gradually "rules
out" candidates but this isn't a prerequisite for counting lower prefs.)

> 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.

However, if my answer might harm my favorite, and I think other voters
may help my favorite, then I could conclude that I shouldn't risk harming
him.

> 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.

Ok.

> >  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.

Well, I hardly think that can be said as a general rule without regard
to what election method is being discussed. Personally where I withhold
preferences in Bucklin is not going to be the same as where I withhold
preferences in IRV.

> 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."

That's not an assumption, that's a definition. If you're not listing
lower preferences because you *perceive a risk* to doing so, that is what
we usually consider "not sincere."

There could certainly be *useful information* in where people 
strategically truncate, but that doesn't mean we call it "sincere."

> >  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.

That's something to debate, but the only point I was making is that
LNHarm and other criteria are philosophically aimed at the good of the
electorate. All things being equal "sincere" is better than "insincere."
Maybe there is some incompatible type of voting that is better than
"sincere," but then all things aren't equal.

> 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.

What we would do there is analyze it as a ballot with an explicit
approval cutoff.

I don't really understand how the runoff finalists are selected. Are
you going to let a faction tie two clones in first place and have them
both go to the runoff?

Are your ideas on this at the bottom of this post?

> 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.

But just like with TTR, the fact that there is a second round provides
incentive to *not* find a majority in the first round. That's not
necessarily bad though.

> 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)

Kevin Venzke