[EM] Why I think IRV isn't a serious alternative 2

[Abd ul-Rahman Lomax]

At 04:33 PM 12/6/2008, Kevin Venzke wrote:

>So, to try to summarize. You can argue for Range in two ways. On the
>one hand, if voters really do vote similarly to how they behave under
>the simulations, then Range is the ideal method according to utility.
>On the other hand, if Range doesn't work out that way, no one claims
>it will be any worse than Approval, which many people feel is not too
>bad.

Right. In reality, Range will improve results. A little. What we 
don't know is how much. But Range, unless perhaps it is afflicted by 
poor ballot design, improper suggestions to voters, or bad voter 
education, isn't going to make things worse. Range is nothing other 
than Approval with fractional votes allowed. Just as Approval is 
nothing other than Plurality with voting on more than one candidate 
allowed. (I.e., it is quite analogous to common practice with 
multiple conflicting initiatives, especially if there is a majority 
requirement, where the analogy is practically exact. The vote on each 
candidate is Yes/No. If two get a majority, the one with the most 
votes wins. In initiative practice, if none get a majority, they all 
fail. There is no runoff, but they could be proposed all over again....)

The procedure should be described as "voting," not "rating," just as 
preferential ballots I've seen for RCV in the U.S. only call the 
votes "choices." They do not use the word preference, and voting 
doesn't make a statement about preference. But, nevertheless, that is 
what people will do, mostly, almost all the time. My guess is that 
most don't go far down the allowed ranks, my guess is that a majority 
of ballots are truncated, but I don't know, it's not apparent from 
the results because most of the truncations would be for frontrunners 
in first choice. But it would be in the ballot images available from 
San Francisco.

>So you can argue Range vs. Approval. For me this is a tough fight for
>Range in the absence of a way to show that voters would/should play along
>with it. On the other hand one can always point out that Range won't be
>any worse. But on Approval's side, you can say that it's displeasing
>for the method's results to disfavor those who play along with it.
>If the method is going to degrade towards Approval, it would be nice if
>the degradation were neutral in effect.

This repeats the misconception -- or mistaken emphasis -- that I've 
been struggling against. Range does not "disfavor" those who "play 
along with it." Any "harm" to them is small; as I've written, an 
almost-ideal result instead of the fully-ideal one. I haven't seen 
studies on the variability, i.e., *how much* does an impaired result 
affect the sincere voters. There is no particular reason to expect 
that sincere voters will be specially concentrated into those who 
prefer one option, with maximizers concentrated into another, and 
that is what it takes to get more impact on outcome, otherwise the 
maximizers cancel or average each other out.

However, it's very important to recognize that I'm not proposing 
Range for immediate use in political elections. In another post 
today, I list three immediate priorities and I'll add a little here.

(1) Act to prevent the replacement of Top Two Runoff by Instant 
Runoff Voting, particularly for nonpartisan elections, but also for 
partisan ones. This is a step backwards, typically satisfying cost 
concerns, supposedly -- that's probably a misrepresentation, or at 
least exaggerated -- at the cost of better results. It is arguable 
with a straight face that IRV is an improvement over Plurality for 
partisan elections. But there are better options that are cheaper and 
that perform better under the contingency that a third party actually 
benefits from the improvement and rises in popularity, bring IRV to 
Center Squeeze, which is generally considered a serious problem.

(2) Suggest Approval or Bucklin or other advanced method for use with 
Top Two Runoff primaries, thus addressing the major known problem 
with TTR, which is also Center Squeeze.

(3) Make it known that Approval is a cost-free reform, a drastic 
improvement over Plurality. It really ought to be a no-brainer, if 
the choice is Plurality or Approval.

(4) Make it known that Bucklin is "instant runoff Approval." It 
answers the major objection raised to Approval, the inability to 
express a favorite. It was widely used in the U.S. at one time, and 
it is a bit of a mystery why it disappeared, but there are political 
forces that, here, would act against any preferential voting system. 
It doesn't technically satisfy Later-No-Harm, but its violation of 
that is mild. It does not suffer from Center Squeeze, because it is 
an Approval method which probably encourages broader use of 
additional preferences. As an primary for TTR, it becomes even 
better. (Bucklin has low counting cost as well, and, once a decision 
is made to count a rank, all the votes are counted, thus it falls 
under my Count All the Votes campaign. -- and I prefer that all the 
votes be counted even if they are not necessary to determine a 
winner, this will, in the long run, encourage more use of additional 
preferences, and it is less work to count the votes than the public 
put into casting them, I consider it rude not to count them.)

(5) Let Range's optimality be known, but I would not put much effort 
into public implementations yet. Approval is a Range method, and 
would educate voters as to how to vote effectively in Range. Then 
adding additional flexibility allows more accurate voting, even 
though many voters won't use it. The additional cost is small to nothing.

(6) Among voting systems theorists and those similarly interested, 
encourage and develop the use of utility analysis and simulations to 
compare voting systems, improving the models used. Work to develop 
consensus on the application of these methods. Compare simulation 
results with real elections where practical, or, working backwards, 
infer or constrain models from real voting patterns.

>Other than that I guess you have to argue Approval vs. other methods.
>That's difficult too.

In the U.S. situation, which I'm mostly concerned with, the concerns 
I state above are paramount. Condorcet methods are certainly 
respectable, but it is easier to implement Approval or Bucklin or, 
for that matter, Range. I find that it's easy enough to use Condorcet 
analysis on a Range ballot, particularly if we are only going to test 
if any candidate beats the Range winner with pairwise analysis, using 
that information to determine a need for a runoff. So, I could see 
this sequence:

1. Top Two Runoff. If it's there, keep it!
2. Bucklin primary. (probably skip Approval, though that's an option, 
with Bucklin following)
3. Fractional vote options. [This could run into constitutional objections.]
4. Condorcet analysis on ballot data, as an additional trigger for runoff.

An ideal ballot would be full-on Range, but I've suggested elsewhere 
that the votes could be phased in, similar to Bucklin, and a voter 
might even be able to prevent the uncovering of a lower preference 
until it's clear that the first preference would be eliminated if 
bottom elimination were used. This would not be full LNH 
compatibility, as it is usually stated, but it would be in substance.

Which is more "harm to the favorite," being eliminated because second 
preference votes from other voters, possibly *many*, can't be 
considered, or not being eliminated but not winning because the voter 
added another preference? Contrary to what is usually said about 
this, with respect to Approval or Bucklin, the voter's ballot, when 
the second preference is counted and added in, doesn't actually count 
*against* the favorite, it merely turns into an effective abstention 
in that pairwise race. I find it weird to call this "harm."


>I wonder if you have ever been curious to wonder what a "strategic" voter
>is, for a rank ballot method.

Nah, curiosity killed the cat.

I've done a fair amount of reading on this, but who remembers 
anything? Often not me.

http://condorcet.org/rp/strategy.shtml has this:

>Strategic voting occurs when a voter does not vote his or her true 
>preference, in the hopes that a false one will get a better result. 
>All the methods that people suggest adopting (including plurality) 
>have some element of strategy. Ranked Pairs is no exception.

Note that the definition does not apply to Approval or Range. The 
first part implies a "true preference" which is not voted, and that 
can happen with these methods, but the second part gives a motive for 
this (which is often a part of the definition: "in the hopes that a 
false one will get a better result." It seems that some might want to 
change this to "in the hopes that not expressing it will get a better 
result." That is actually quite a different statement, in some 
senses. The meaning that the writer had in mind is clear: the 
expression of a false preference, not the nonexpression of a true one.

http://www.allacademic.com/meta/p_mla_apa_research_citation/1/3/7/3/4/p137347_index.html 
has this:

>A strategic vote is generally considered a vote for a second-best 
>alternative that has a greater chance of winning than a preferred 
>alternative. In this study, rates of strategic voting and 
>misrepresentation of preferences are estimated in a model ...

The author, again, has "misrepresentation of preferences" in mind. 
The definition is worded such that it could apply to multiple votes 
in Open Voting.

I looked at a lot of papers and the usage of "strategic voting" was, 
first of all, mostly with reference to Plurality, but, then to 
preference reversal. Now, I didn't include "Approval Voting" in my 
search term. What interests me here is how the term came to be used 
in a highly perjorative sense with application to Approval voting. 
The best place to see this may be with Saari's weird paper:

Is Approval Voting an Unmitigated Evil? A Response to Brams, 
Fishburn, and Merrill. Happens to be a copy at

http://rangevoting.org/UnmitEvil.pdf

He claims to show that "AV is one of the most susceptible systems to 
manipulation by small groups of voters (e.g., the outcome could be 
determined by small, maverick groups.)"

"Manipulation" carries with it the smell of strategic voting. These 
are "small" groups, and should small groups of voters be able to 
determine an election outcome? They certainly can if the rest of the 
electorate is essentially tied! "Maverick" What does that have to do 
with it? Let's see what he does. As I proceed with reading the paper 
how he begins by repeating the claim, without evidence, but with 
simply variations of the claim:

"The more negative features of AV." "AV gets bad grades." "Why should 
we consider a voting system with defects so serious that they violate 
the purpose of an election?" All this, before he's actually stated 
the defects, other than to give one of them a name: indeterminacy. I 
agree, though, with Smith: Saari is incoherent. This paper was way 
below a standard expected in peer-reviewed material.

So what kind of example does he have in mind. First of all, it's 
pretty frustrating to read this paper. It is mostly repetition of the 
claim that Approval is a terrible system because it is indeterminate 
and this can produce awful rules, why should we use such a horrible 
method, Saari's paper is worse than a badly-written rant on this 
list. It's even worse than my writing! Yet there is was in Public Choice, 1988.

Out of 10,000 voters ranking the candidates A, B, C, 9,999 believe 
that A will do an excellent job, that B is quite mediocre but much 
preferred to C, and that C is an absolute disaster. The last voter 
prefers C but believes that B is much better than A. Using "BFM's 
recommended strategy of mean utility," each voter votes for his or 
her top two choices. The AV tally for the first 9,999 voters is a tie 
vote between A and B. This tie is broken between A and B when the 
last voter votes. So excellence is the clear choice of these voters, 
but AV selects mediocrity. And then he refers to small groups of 
mavericks altering the outcome.

This is really appalling. Is he pulling our leg? Apparently not. He 
believes what he's writing, it seems. "Excellence" was not the "clear 
choice" of those voters. Saari imagined that they had a preference 
profile that would imply excellence as the choice, but they 
*certainly* did not choose to actually *make* that choice. Rather, 
they indicated indifference, all 9,999 of them. How does Saari 
justify this bizarre voting pattern?

By the way, the C voter is rational. I'd vote that way if I were C, 
because B is clearly an improvement over the expected outcome, if C 
has any clue as to the context. The only way that the 9,999 voter 
votes are rational is that none of them have any clue about how the 
others might vote. It's zero knowledge. "Mean utility" as a strategy 
would be used on with zero knowledge, as one option, and I've 
discussed elsewhere in this series of posts that voting mean utility 
as an approval cutoff, is probably a Bad Idea, there is a better way 
of estimating zero-knowledge election utilities, which is to assume 
that the average voter is like you. It's true more often than not. 
Real voters, absent a rough assessment of probabilities, are likely 
to bullet vote unless their preference strength is small. Saari's 
example is preposterous, it posited absolutely uniform decisions by 
9,999 voters, when, in fact, the voters are not identical, they are 
spread, they will make different decisions. In a real election like 
this, with, somehow, the voters would differ in their decisions of 
where to place the approval cutoff and, as it must be noted, if even 
one doesn't vote for B, it's a tie, and if 2, still a tiny, tiny 
percentage, don't vote for B, excellence wins.

The problem here is that the voters do *not* vote with any real 
strategy, as we have been discussing strategic voting, they vote with 
a mindless rule that Saari seems to think was recommended. I agree 
that Brams and Fishburn may have overestimated the degree to which 
voters will add additional approvals. Results with Bucklin in primary 
elections seem to have shown that only about 11 percent of voters did 
so, and Bucklin makes it easier to add approvals, because they are 
not counted at first. Majority failure was apparently common, as one 
might expect. Bucklin doesn't fix all problems! The key would be to 
hold a runoff when there is majority failure, and, in fact, IRV had 
similar problems when used for primaries in the U.S., I understand; 
and IRV was replaced with top two runoff as a reform.

Dhillon and Mertens get it right: they think that Approval voters 
will vote VNM utilities, not raw utilities with some mindless mean as 
a cutoff. If 9,999 voters express indifference between A and B, *of 
course* a single voter can make the choice! Those weren't voters, 
they were figments.

I was looking for usages of "strategic voting," but came across this 
Saari paper again. Sorry.






>Where does truncation fit in? Surely truncation was seen as a strategy
>concern, considering how old STV is.

Truncation as a strategy is problematic. It's simply equal-ranking 
bottom. It does not express preference, and if there are meaningful 
preferences there, we could consider the vote inaccurate. But it is 
not insincere. Truncation does two things: it is effectively a vote 
against all those candidates, or, more accurately, the expressed 
votes are votes against all the nonranked candidates, it expresses 
indifference between them, and it may cause majority failure if that 
is required.

And if a majority is required, truncation is a sincere strategy that 
clearly can improve the outcome. It's sincere because it really does 
state that one prefers all the ranked candidates to the ones not 
ranked, which is the necessary for the effect to be an improvement, 
and because if none of the "approved candidates" -- those receiving 
votes -- are elected, the remaining effect of the vote is to cause a 
runoff or further process where one of these or even one better may 
win. And the voter can decide later if preference strengths make it 
worth voting in the runoff.

Indeed, with IRV, truncation allowed and a majority required (the 
Robert's Rules version), truncation even after the first preference 
can be a reasonable strategy. To me, the issue is whether or not the 
voter prefers to rank another candidate or to cause majority failure. 
If I'd rather see majority failure, there is where I stop ranking. 
*And this improves outcomes, not just for me, but for the overall 
result, and how much depends on the method.*


> > An inaccurate vote with Range isn't necessarily
> > insincere, at all. The voter has decided not to put more
> > effort into determining relative utilities. The voter simply
> > has not considered other than two frontrunners. The voter
> > has simply decided that full-on Yes and No are adequate
> > expressions.
>
>Sure, but that is insincere *enough* to say that it's not what would
>be expected by the simulations for a sincere voter.

That's because "sincere voter" in Range is specially defined to 
include an accurate representation of relative utilities, generally. 
That's "sincere Range" in the simulations. I don't think that 
inaccuracy was considered. Naturally, better models would do so.

But these aren't going to change relative results much, I'm pretty confident.
>With Approval it's difficult to find "obvious best winners." The
>notion of a candidate "representing" voters is difficult considering
>that voters, especially in Approval, are mostly just making strategic
>decisions when they vote.

Well, no. They are combining utilities and preference order 
information with probabilities. The former are most important, the 
votes are meaningless without them. The vote will vary between bullet 
voting and antiplurality. The Saari example was actually 
antiplurality. Utterly the opposite of what I'd expect in real 
Approval elections. In a deliberative environment, if Approval is 
used to speed things up, the expectation would be that you would not 
add additional approvals unless the preference strength is weak 
enough that you'd rather see the process terminate earlier than 
later. With significant preferences, you would start with a bullet 
vote, then, each new election, you would lower the approval cutoff 
until a majority is finally found. Those who resist adding additional 
approvals have higher absolute preference strength, it is practically 
necessary.

And that's how it actually works in a real environment where a 
majority is required. Quite often, depending on how many candidates 
there are, a majority is found in the first ballot. But with many 
candidates each with many supporters, majority failure becomes the 
norm, especially in the first round.

>If we expect two frontrunners under Approval, I would be very surprised
>(and extremely put off) if Approval ended up failing to produce
>majorities. This would go most of the way to convincing me that the
>incentives are broken.

Well, maybe, but you would be foolish to expect Approval to be *much* 
better than Plurality at finding a majority. IRV does a little better 
(I mean real majority, of course). Bucklin probably a little better 
at that. Approval will probably be not as good as Bucklin at finding 
majorities.

Approval, one has to understand, is the no-cost reform, not the ideal 
one. It's a great place to start, because it sets up the idea of 
voting independently on each candidate. That's necessary for SWF maximization.


> > > If two candidates obtain majority approval, most
> > likely one of them was
> > > not a frontrunner, but a compromise choice.
> >
> > That's correct, if "frontrunner" refers only
> > to first preference. If it refers to overall popularity,
> > predicted approval votes, it's a different matter, and
> > one that I did not consider above.
>
>This is actually interesting now that I think about it.

Right. However, it's addressed pretty effectively by polling for 
expected votes given the voting system. If the voters know that the 
real race is between A and B, not A and C, they will tend to place 
the approval cutoff between A and B, thus discriminating between two 
good candidates, perhaps. If the significantly worse candidate, C, is 
in Range of winning, voters will shift their approval cutoff to be 
making the important choice, between the A,B set and C.


>Some six months ago I wrote a strategy simulation for a number of
>methods. One situation I tested was Approval, given a one-dimensional
>spectrum and about five candidates, A B C D E.
>
>In my simulation, once it was evident that C was likely to win, one of
>either B or D's supporters would stop exclusively voting for that
>candidate, and would vote also for C.

B and D voters are motivated to ensure that C wins if their favorite 
doesn't. Hence Approval will tend to find a compromise. If B or D are 
not relevant, can't win, they *may* also vote for B or D, so I'm not 
sure that the simulation was accurate. The vote would depend on 
preference strenth in the pair involving C and their favorite. If 
weak, more likely to also approve, but, note, this doesn't, by 
definition, affect the outcome unless they have bad information.

In a real situation, the likelihood of bullet voting varies with 
utility distance, i.e, preference strength. If we look at a voter 
equidistant between B and C, the voter may actually have minimal 
preference between B and C and even have difficulty deciding which to 
vote for as a first preference. For some region between B and C 
voting for both in Approval will be common.

As C becomes a frontrunner, and unless B is a frontrunner also, the 
probability that the voter, considering this, will also vote for C 
increases. It's simply VNM utilities. You place the vote strength 
where your limited investment can make a difference. In Approval and 
Range you have a full vote to "spend." If we lay the candidates out 
in a spectrum, in preference order, accurately, where we place the 
vote is only proportional to the absolute preference strength in a 
true zero knowledge vote. The real vote will depend both on the 
preference strength and on the probability of the vote making a 
difference. No such probability, the preference order remains the 
same, but no vote strength is invested in the election pair, and 
approval allows you to place that vote in only one pair, but it then 
operates on all pairs straddling that pair. It's a choice. The power 
of the choice improves with better knowledge. Big surprise eh? 
Approval rewards having better knowledge, I think that is a good 
effect. But even those with zero knowledge of the probabilities (how 
could that happen with a voter who was at the same time informed 
about the candidates?) can contribute something: that's the vote that 
Saari claims was "recommended," or, better, the bullet vote, just 
vote for your favorite. It is as sincere a vote as is possible in 
Approval, it expresses exclusive preference, this one over all 
others, which is the kind of preference people are accustomed to 
expressing. In the sorry Saari scenario, that simple vote, from two 
out of 9,999 voter who were not under the evil influence of Brams, 
Fishbrurn and Merrill's plot to teach voters how to elect mediocre 
candidates, would have saved the day. Saari posited stupid voters, 
then proposes, elsewhere, that Approval is a system for unsophisticated voters.

>So then, the frontrunners really were either B and C, or C and D. (And
>C would almost always win.)
>
>If Approval managed to behave like that, I would consider it pretty good.
>I wonder if it can be tweaked to make this scenario more likely to occur.

But that is how Approval would tend to work. You add additional 
approvals when your preference strength between the candidates is 
weak. You don't when it is strong. In the scenario you posited, there 
may have been, initially, five frontrunners, based on first 
preference, which was based on issue distance. But if you look 
carefully, for a region between each of the candidates, there is a 
region where preference strength is weak, even if the candidates are 
spread apart; it's that the voters involved are between their 
positions. Those voters will add additional preferences. But majority 
failure is still likely to occur in a real election. Beware of 
setting up an election scenario that is exquisitely balanced; with 
five candidates it is very, very rare. Three in balance is rare enough.

Your simulation allows a determination of relative preferences, which 
into "sincere Range votes" if you want to study that. It occurs to me 
to add a responsiveness factor. Some voters have little overall 
preference strength across the entire candidate set, and others have 
strong preference. If this were a special election (like a runoff, as 
an example), the absolute preference strength will affect turnout. 
Low absolute preference, low range of utilities possible between the 
best outcome and any of the others, lower motivation to turn out and 
vote. But also higher likelihood of adding additional approvals.


> > If more than one candidate receives a vote from a majority
> > of voters, there will also be a runoff election between the
> > top two.
>
>I don't think it is viable to have a runoff election between the top
>two Approval candidates. I know you have hinted that you're not concerned
>about Clone-Loser failures here.

Approval is basically tweaked Plurality. I'm simply considering a 
double majority as a kind of majority failure, the majority has 
failed to clearly indicate a preference. If A and B both gain a 
majority, and A has more votes, we do not know that a majority favor 
A over B. It might be as few as the difference in votes that have 
that preference, or, in fact, as would be asserted by the MC 
criterion failure, it might be as large as the vote for A. A runoff 
test this. Yes, I'm not so concerned about strategic nomination to 
try to get two candidates into the runoff. That strikes me as very 
foolish politically, the likely result is that neither would make it. 
There is still some level of vote-splitting in Approval, particularly 
if both are frontrunners, plus there is the problem of trying to get 
name recognition for two candidates instead of just one. Not 
efficient. Pick the best candidate and put all the effort into that 
one. Approval is just a minor tweak.

The point of using Approval in a TTR primary is that it is more 
likely to detect a compromise winner in the primary. Bucklin, 
probably more. Condorcet methods, certainly; but they will need an 
explicit approval cutoff. Not hard to do. (It's like Range; range 
bears a relationship to fully-ranked methods if it has sufficient resolution.

> > In order to do it, we need a method of *measurement* of
> > election performance. Enter, stage right, Bayesian regret.
> > Got any other alternative? Has any other alternative been
> > seriously proposed?
>
>I don't think so. We just called it "social utility."

Right. Bayesian regret, for onlookers, is simply the difference 
between the ideal result, the social utility maximizer, and the 
actual election victor. It's calculated as an average, in the 
simulations, over many elections with vary assignments of candidates 
to positions and derived voter preferences. Less regret is better. If 
the perfect choice could be made every time, that would be zero 
regret. No known method achieves that, unless we make very 
unrealistic assumptions about the voters.

However, there has been no attempt to study, say, Asset Voting with 
regard to Bayesian regret. It could be argued that Asset Voting 
creates an electoral college with zero deviation from ideal, since 
every voter is represented there, full strength, by their ideal 
choice, without opposition. The translation from that into an 
assembly can be quite close, but there will be deviations, if small, 
from full representation.


> > > (It works when we
> > > > can see it and test it, why would it stop working
> > when we
> > > > can't?)
> > >
> > > Because real people will be involved
> >
> > That doesn't actually answer the question.
>
>Well, if it doesn't work when we can't see and test it, the reason likely
>has something to do with real people being involved.

There is no question that real results can differ when the 
circumstances change! It's just that we learn as chldren than when 
someone walking passes behind some obstacle, they *often* appear on 
the other side a a time correlated with the distance and how fast 
they were walking. We learn to assume that they continue walking, as 
a first estimate, when they pass out of sight. It's an assumption 
that is more often correct than false.

If we know that a method works when utilities can be measured, there 
is no particular reason to suspect that it will stop working when 
they cannot be. Preference strength is real, it motivates people, and 
it can sometimes be measured. But it was assumed that it was 
meaningless by people like Arrow, because there is no specific 
general metric for it.

Dhillon and Mertens finesse this: they define the preference strength 
by what a voter expresses! And this is pretty much the conclusion I 
came to. Expressing a strong preference takes, at least, a *kind* of 
strong preference. That the voting is a lottery, and that, in Range 
Voting, one cannot simultaneously bet the same vote on all pairs, but 
only spread it and allocated it between pairs, total strength one 
vote, is a restriction on the vote that encourages a kind of 
sincerity. It is simply that this is modified by probabilities, and 
economists were accustomed to this kind of choice, that's VNM utility.

> > What questions remain? I see substantial agreement in
> > certain areas. What do you think?
>
>It is possible that we are getting closer.

That's the goal of discussion, isn't it? Discussion to win is rather 
boring and usually goes nowhere, at least here.


>My original concern is to try to reconcile the ideas that simulations
>support Range and yet real voters should not be expected to mimic their
>mind-read votes from the simulations.

Yes, of course. But real voters will follow something similar. It's 
unpredictable, Saari was right that Approval is indeterminate, but 
Brams and Fishburn were right that it is a feature, not a bug.

It gets harder, not easier, to manipulate other voters when their 
votes are indeterminate. Saari fell into the trap of imagining that 
indeterminacy would allow a group of "maverick voters" to manipulate 
results, but his example showed something very different: a long 
voter (maverick?) who votes sensibly and who determines the outcome, 
since everyone else votes in a totally predictable and uniform way, 
hence failing to express an important preference and ending up with a 
mediocre election outcome. That wasn't really, a mediocre outcome, 
that was a poor outcome, with have the SU of the ideal, pretty much. 
That's big regret, produced by stupid strategy, applied by 9,999 out 
of 10,000 voters who were totally clueless.

>It strikes me that ultimately you don't really need the simulations,
>because you can argue in any case that Range will be at worst as good
>as Approval. If you can sell Approval you can start selling Range,
>basically.

Actually, that's my conclusion, politically. Start with Approval.

Count All the Votes.

Like, Duh! What took us so long to figure this out? It's not like it 
was never done before.

However, the simulations are important because they lay a framework 
for studying voting system performance that isn't so thoroughly 
subjective as the criteria turnout out to be. The measure of 
performance works when the outcomes can be actually assessed, as 
with, for example, the placement of a capital problem based on a 
population of users who would all like to be at a minimum distance to 
the capital. For each voter, we could determine exact travel 
distance, and we could assume that we want to minimize, assuming, 
say, one trip to the capital each year, total distance travelled.

So, as you did, we can use issue distance to estimate preference 
strengths, in simulations. We can theorize at length on why this or 
that system is better, but performance in simulations should 
generally be stronger as evidence.