[EM] Condorcet vs Range (Greg Nisbet)

[Greg Nisbet]

Message: 2
Date: Sat, 11 Oct 2008 18:29:48 +0000 (GMT)
From: Kevin Venzke <stepjak at yahoo.fr>
Subject: Re: [EM] Range > Condorcet (No idea who started this
       argument,       sorry; I am Gregory Nisbet)
To: election-methods at electorama.com
Message-ID: <437126.5268.qm at web23301.mail.ird.yahoo.com>
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Hello,

--- En date de?: Sam 11.10.08, Greg Nisbet <gregory.nisbet at gmail.com> a
?crit?:
> De: Greg Nisbet <gregory.nisbet at gmail.com>
> Objet: [EM] Range > Condorcet (No idea who started this argument, sorry; I
am Gregory Nisbet)
> ?: election-methods at lists.electorama.com
> Date: Samedi 11 Octobre 2008, 2h01
> Reasons why Range is better and always will be.
> I would like to end the truce.
>
> I'll be generous to the Condorcet camp and assume they
> suggest something
> reasonable like RP, Schulze or River.

I suggest Condorcet//Approval with ranking among disapproved candidates
disallowed. Though apparently you are adamant about Clone-Winner
compliance.

I merely said that of the methods I am aware of, Schulze, River, and RP are
the best. Condorcet-Approval certainly sounds interesting though. I heard
about another hybrid today that also looks promising. Elect the Condorcet
winner if there is one otherwise default to approval. I think in practice
this would mostly result in the Approval winner being elected anyway. I
admit it. I completely overlooked Range-Condorcet hybrids. This one,
http://fc.antioch.edu/~james_green-armytage/cwp13.htm, also looks
interesting by the way. My response to these is largely the Bayesian Regret
argument. As near as I can tell, this preliminary procedure will reduce
overall Bayesian Regret scores.

I'm not entirely sure when the ranking of the disapproved candidates would
throw out the approval winner. (Which logically it must if it is to be
different.) I'll look for it though.


(I also suggest my FBC tweak of this method, but then we have exited 100%
Condorcet compliance.)

Interesting…


> Property Related:
> favorite betrayal, participation and consistency.
> Implications:
> 1) It is always good to vote and it is always good to rate
> your favorite
> candidate 100. The only Condorcet method to satisfy
> favorite betrayal is an
> obscure variant of Minmax which I'll ignore because of
> its glaring flaws (clone dependence *cough*)

MMPO fails clone independence rarely; the difficulty with it is its
potential to give absurd results failing Woodall's Plurality criterion
(is how I would describe it).



Wouldn't MMPO<http://www.mail-archive.com/election-methods-electorama.com@electorama.com/msg06261.html>be
susceptible to the other arguments as well? At first glance, it does
appear promising.

> 2) How does it make sense to be able to divide a region
> into two
> constituencies each electing A if B is the actual winner?

I would say it doesn't matter. I'd also say that in reality, Range isn't
better, even if technically it doesn't seem to have this problem. So
it's purely a theoretical concern.



It may be a theoretical concern, but saying it doesn't matter really isn't a
response. I was wondering how a method failing this could be considered to
truly represent the will of the people when considering them as several
independent groups would lead to unanimous support of a different candidate.
I did not link this argument back to the real world of voting; I
specifically asked for a theoretical justification.

> Condorcet methods
> are not additive, this calls into question the actual
> meaning of being
> elected by a Condorcet method.

It would, if one did not know what the meaning is. Of course the CW is
not selected on some additive reasoning.

This is my argument. Please defend the concept of a CW given its
non-additive properties.

> answers to potentital majority rule counterarguments:
> 1) Range voting isn't a majority method.
> answer: any majority can impose their will if they choose
> to exercise it.

The reason this is not a satisfying answer is that when a method is a
"majority method" this means that the majority does not have to get
together before the election, identify themselves as being a majority,
and settle on a singular goal.

Otherwise almost every method is a "majority method" in your sense.
Plurality is one too.

First of all, I wasn't suggesting this as an alternative definition of the
majority criterion. Also, in order for a method to escape your criticism it
would have to satisfy FBC and majority at the same time so that sincere
majorities can be identified and rewarded. Please identify a method that
does both of these.

My point is that a strategic majority will always be rewarded. The majority
does not have to organize itself before the election; they just have to
individually be unwilling to compromise.

For the point regarding FPTP, it is a majority method. It is not a good
majority method by any stretch of the imagination, but it nevertheless is
one.

Another response to this argument:

What happens if you combine the majority criterion with Range Voting. Have
an initial step to check for a majority winner and then proceed with normal
Range Voting if a majority winner is not found. Presumably this would answer
the argument. Well, not really. It would encourage people to vote for a
compromise candidate in the hopes of guaranteeing them a majority and thus
violate FBC by forcing them to shove their true favorite into second place.
Compliance with the majority criterion would destroy FBC compliance. (you
might be able to make it so that the single vote for a candidate to attempt
to get a majority were separate from the range ballot, but this would again
violate FBC)

> concession: it is true that Condorcet methods solve the
> Burr Dilemma fairly
> well because parties can simultaneously compete for
> majorities and swap
> second place votes. Range Voting can at best allow voters
> to differentiate
> between better and worse candidates by one point. So
> Range's ability to
> emulate this behavior is competitive.

That is a charitable description of Range's capability here, since
with good strategy the differentiation between any two candidates is
either zero or the entirety of the range.

Really though, I do not think Condorcet is too great in this respect.

So we agree on something! Hooray! Shifting gears somewhat,


> Understandability:
>
> Range Voting (I dare anyone to challenge me on this)

Jobst criticizes that the numbers are meaningless. I would not criticize
this, except that it does not even seem to be possible to use strategy
to come up with a practical meaning of the intermediate ratings.

I could imagine someone perhaps complaining that the meaning of rankings
is not clear. (Perhaps they believe real preference rankings are not always
transitive.) But when you know what the rankings are supposed to do and
when and how to use them effectively under whatever method, you can still
figure out the practical meaning of a ranking, even if it does not mirror
your real and complete sentiments.

With Range this seems lacking.

The point of understandability isn't conceptual but rather a reference to
how long it takes to explain to the average person how the voting method
works. Your counterargument does not apply to my original point, but I
explained it badly so it's my fault. Criticizing the concepts as
meaningless, I like that. Especially since that is what I was doing with my
consistency failure remark. You can't have it both ways; either
philosophical attacks are valid or they are not. Let's assume that they are.
You say the magnitude of comparisons is not really substantiated by anything
thus their magnitude shouldn't be considered (as almost all Condorcet
methods actually behave). I disagree. I say Range Voting minimally distorts
the concept of utility, just as you claim Condorcet methods minimally
distort the concept of decision-making. Two limitations are placed on
allowable votes in range voting, lower and upper bounds, (they must be
integers as well, but this point is not especially relevant). This is
designed to defend the system from dishonest utility monsters (e.g.
Candidate A +1000000000000000000000). I'd say the concept of utility is
intuitive. It is very similar to the concept of money. You understand that
$1 > $.99 and that $45 > $1. It is intuitive that $45 is much, much better
than $1 than $1 is than $.99. Range Voting is a single dimension of
comparison. Keeping with the Enlightenment style assumptions, human opinions
should be perfectly transitive and rational, yes. So, a preference ballot is
the most information that a human can be relied upon to fill out with 100%
accuracy assuming they are rational (use of singular they to avoid sexism).
I'd say sacrificing 100% accuracy for the vast amount of additional
information you can gain from a cardinal ballot is worth it. Given that it
seems natural to classify candidate worth along a single dimension to most
people.



> Bayesian Regret:
>
> Range Voting (same comment)

This is trivial to dispute unless you claim that everybody is voting
sincerely under Range. Or, you claim that Warren's simulations do not
have all the limitations that they actually do. In these cases, no, that
cannot be disputed, that Range reigns supreme.

To my knowledge, he used strategic voters as well as well as a noise
generator to represent ignorance. I have an idea to simulate perfect
strategy. Organize the voters from early to late, have them try maybe 20
randomly generated votes, whichever one affects the outcome most to their
liking will be selected. It seems like a fair way to test strategy. It's
probably already been done, but I'll write a simulation for it later. I
plead ignorance here; I do not know what the limitations are. They seem to
approximate the behavior of real voters to me. If not, please suggest an
experiment that will.

> Ballot expressiveness:

Pure expressiveness is useless. What should be compared instead is the
degree of expression possible after rational strategy is employed.

In order for post-strategy expressiveness to be present, pre-strategy
expressiveness must be present. Please prove that a) all the expressiveness
in Condorcet is preserved post-strategy and b) None of the range
expressiveness is.
> Bottom line:
>
> Range: You can express apathy, but you take your life in
> your hands.

On the contrary, you take your life in your hands when you do not
use the min/max ratings. That is why I prefer Approval: Why invite the
voter to take their life in their hands when it is totally unnecessary?

First of all, non min-max ratings have a defined meaning when you rate
everyone because their averages will change in a way consistent with how you
intended your vote. That is my point. As long as you rate everyone, their
averages will be altered according to your vote. My apathy argument (against
range voting, I might add) is that unless you guess accurately what the
averages for the candidates will be, it could backfire. Condorcet does a
great job of isolating apathy as you can specify which comparisons
specifically you are apathetic about (with creative ballot design of
course), but at least the capacity exists. For example, by ranking candidate
B and E the same, you can compare their superposition to all other
candidates but express apathy about which is better. In order to emulate
that behavior in range, you have to give them the same exact rating, which
is functionally equivalent but less tidy thus inviting other problems in
more complicated examples (like the one I gave originally)

I think you mean "in addition", the CRV website does mention some cases in
which, for a large electorate pool, intermediate ratings are strategic
because the voting patterns of all voters cannot be predicted perfectly,
thus it is best on average to use intermediate scores. Later I'll do a, "how
much do honest voters shoot themselves in the foot?" test, but please
suggest some benchmark nonrange method to compare it to.

>  If I overlooked something or made an error, please tell
> me; I'm just a high
> school student.

I wonder if the CRV is your introduction to voting systems? I am a little
curious where the Range advocates come from.

It is part of it. I don't take their statements on faith, though. I've
studied game theory a bit and have the websites that advocate various other
methods: IRV <http://www.fairvote.org/irv/>, Borda <http://www.deborda.org/>,
Condorcet <http://condorcet.org/>, Condorcet (as near as I can
tell)<http://www.barnsdle.demon.co.uk/vote/vote.html>,
various <http://aceproject.org/>. Some of the newer hybrids such as MPPO,
majority choice approval and such I am not that well read on. Si vous savez
où je peux en apprendre plus, dites-moi. For some reason, I cannot access
the Electorama pages, it sort of annoys me. Anyway, I do recognize the
faults of Range Voting. I mentioned them specifically, like the results of
expressing apathy and exposure to the Burr Dilemma. I do not worship the
CRV; I merely agree with them on most issues. I come from California. I am
not quite sure if that is the intent of the question. I studied politics one
day on Wikipedia and came across something about PR, I think and read all of
the articles about anything remotely voting related. The articles on CRV
were coherent and, unlike Fairvote or de Borda, did not ignore the flaws
with their own system. I even read some of Saari's work before deciding that
he was advocating Borda with arguments that actually support Range Voting
better. Anyway, IRV and Borda seem pointless, once I understood Schulze and
RP, it became tougher to tell which was better, them or Range. I decided
Range on the grounds of the FBC criterion, ease of use, simplicity, and
sidestepping the crushing limitations of Arrow's impossibility theorem. I
don't think I'm a normal Range Voting advocate. I have no idea how old any
of you are, but I imagine you aren't 16.

I realize the game theoretical nature of the arguments used to support
Condorcet methods. It is all based on providing absolute certainty to voters
that their vote will never lead to paradoxical behavior Y in method X. I
understand the specific ordeals that Condorcet helps to diffuse. I think the
best argument I can possibly think of for supporting Range is this. Start
out with the (very charitable) assumption that the properties attributed to
the Condorcet methods are about equal in value to the ones that Range
satisfies. Now, there isn't one Condorcet method that satisfies all of them,
in fact the existence of one that does so is impossible. At the end of the
day you are left with a nebulous group of methods that satisfy an impressive
group of criteria some of the time and a simple method that satisfies some
very powerful criteria and can be explained to a small child in about three
minutes. Which would you choose?
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