Tideman Criticism of Range Voting –
response by Abd ul-Rahman Lomax
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T.N.Tideman [in email]: |
Tideman has succinctly stated a common
argument against Range. But it's a defective argument.
Range is untried in public elections, so we
really don't know how it will behave, we only have theory – and, as we
all know, people can have conflicting theories. But there are some very good
arguments for Range, I think good enough, by far, that Range deserves to be
tried. In my opinion, it is at least as good as IRV, and, actually, should be a
lot better.... of course, we need to define what "better"
means. We have no consensus on that. (By "we" I mean the election
methods community. Range voting advocates do have a metric for "better." But it has not been
universally accepted.)
Here are the flaws in the argument:
(1) There is no "pretense that people
are supposed to vote sincerely" under Range. Voters may vote as they
choose, they are not constrained. Indeed, what seems to be objectionable to so
many critics is that voters have choices with Range that they don't have with
pure ranked methods, i.e., methods which neglect preference strength or only
use an imputed strength to discriminate between members of the Smith set.
(2) There is a hidden contradiction in the
argument. Suppposedly there are some people who vote "sincerely," and
others who vote "strategically." However, nobody tells you how to
rate candidates in Range. Under Approval, there is a strategy which is
suggested only, and which is anything but insincere. Essentially it suggests
that one draw a line somewhere between the two pre-election-poll frontrunners,
and approve everybody above that line in quality. This is clearly sincere.
That one might not "approve" of a
candidate one votes for under this strategy is moot. The name of the method is
modern and not entirely accurate. Approval is merely standard FPTP voting with overvoting allowed.
Continuing the discussion of the
contradiction: supposedly Range rewards "insincere" voting. In order
to draw this conclusion, one must assume that "bullet" voting (voting
for one only, at 100%) is insincere. However, what bullet voting amounts to,
assuming that one gives the maximum rating to one's true favorite, is setting
the Approval cutoff at one's favorite, and then setting what I call the
magnification high enough that all other candidates are disapproved. It's not
insincere. It is merely, at most, melodramatic or exaggerated.
Now, why would one do this? Why would one
"exaggerate"? Remember, there is no fixed standard for rating
candidates, but we can assume that ratings correspond to rankings, that is,
that ratings will be in the same sequence of magnitude as would correspond with
rankings. Truly insincere voting would involve rating candidates out of
sequence, not compressing the scale such that all candidates are ranked either
at maximum or minimum.
One would exaggerate if the outcome of the
election, that one's favorite wins over all others, is important to the
voter.
Now, if all voters vote in this way, Range
reduces to Approval, which, as has been stated and which seems to be a rather
common opinion, is not at all a bad method. Here, though, it is asserted that
Range rewards "insincerity," which, in context must mean that it
harms sincere voters. Sincere voters, it is assumed, have voted other than the
extremes. That is, if they like B almost as much as A, their favorite, they may
rank A at 100% and B, say, at 80%. Now, it is absolutely true that this could
result in the loss of the election by A to B, particularly if B voters do not
similarly rate A (which, if we assume that sincere votes have to do with
position in issue space or affinity space, might seem likely). But this only
will happen if most A voters really don't mind B winning the election. In other
words, the harm to them is small, relatively speaking.
What seems offensive is that B voters have
been "rewarded" for voting "insincerely." But it
mattered to them. Who are we to claim that their expressed preference and
ratings are "insincere"?
Range allows – but does not
require – voters to express a "weak" vote for one candidate,
while at the same time expressing a "strong" vote for another. Voters
are not required to do so, they will only do it, I presume, if their preference
of the strong over the weakly approved candidate is not strong.
Range leaves to each voter the decision of
how to rate candidates. I assume that some parties and candidates will try to
get their supporters to bullet vote for them. Some critics seem to assume that all
candidates would do this. But consider this: I would consider it a strong
negative consideration for a candidate to refuse to acknowledge that an
opponent might be a good choice as well. It means to me that the candidate is
either insincere or is a fanatic. Our present system requires candidates
to more or less behave in this way, so it does not reflect on them individually
at present. In other words, for a candidate to engage in puffery is not, at
present, for me, a disqualification. However, with Range, it would be.
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If you are going to have a system in which knowledgeable people use what looks like approval voting, then in my view you should invite everyone to cast approval votes. |
It is simply not true. It is not true that
"knowledgeable people" would vote only approval style. I wouldn't.
Unless the candidates were so far apart that I could only approve one of them,
or a few. Indeed, I might do this, but in many elections I would not. It
depends on how important it is for my favorite to win or my most-disliked to
lose. Depending on the importance, I would "set the
magnification."
What Range does (like Approval) is to equate
the "selection space" of all voters. Your maximum rating is the same
as my maximum rating, and your minimum is the same as mine. That's a
simplifying assumption and it is probably not literally true from a social
welfare point of view, but it is a necessary assumption unless we get
something like delegable proxy, where elections could become a deliberative
process where it is possible to consider, for example, the expertise of voters.
Absent something like that, which would assume general consent to such a
process, we must assume that all voters have an equal right to influence the
outcome.
But having a right does not mean that one is
required to exercise it at all, or, in this case, to exercise it fully. Range
gives me the choice. Where it is important to me, I can
"exaggerate." Where it is not important, I can give graduated ratings.
This, in fact, is only an expression of how I rank importance. It is not at all
insincere, whether I exaggerate (bullet vote or Approval vote) or spread out my
ratings.
I think that the idea that Range somehow
rewards insincerity comes from a paradoxical realization that there is
something good about allowing voters to express intermediate ratings.
Supposedly such voters, the thinking would be, are superior to voters who only
will vote for their favorite and against everyone else. And then by "allowing
the inferior voters to prevail," we have somehow turned this on its head.
It's a paradox. In order to avoid the alleged harm of allowing intermediate
votes, which we somehow sense are good, being sincere, we prohibit them....
But there is no harm that is not accepted
by the sincere Range voter.
The most harm is done, in particular, to
voters who truly vote out of sequence. I.e., they favor A>B>C (A
over B over C), but because they fear that B will win, they rank A highest
(sincere), B at zero (which could be sincere in itself), but C at an
intermediate rating, or even at full rating. If it happens that C wins, because
too many voters think similarly, they will experience the full consequences of
their insincerity – maximized regret.
And this will only happen if, say, other
voters, say B supporters, rank C at some higher rating than zero. (I'm assuming
here that the honest Condorcet winner would be B.)
|
But I am not happy with approval either. I think we agree that under approval the strategy that generally makes sense is to try to determine which two candidates are most likely to be ranked first and second, and then give a vote to the one you favor between these two, and to all candidates whom you prefer to that candidate. |
Yes. Range strategy is quite similar; the
only question is the "magnification," which most writers on the
subject seem to have neglected, as if it were obvious how to
"sincerely" distribute intermediate ratings, as if it is necessary that
if I prefer A to B, I must rate A over B. Sure, I must, if the system allows
me sufficient resolution. It won't in many cases. What must be understood
is that the distribution depends on the importance that the voter places on the
victory of the favorite over others and the loss of the most disliked compared
to others. With strong preferences in this regard, Approval style voting is sincere.
And if preferences are weak, then intermediate ratings do not harm the goal of
the voter: a pleasing outcome to the election.
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If I wanted to devise an evaluation of Approval that I regarded as informative, it would need to involve a statistical process that reflected this understanding of how approval works in practice. But even if that evaluation turned out well, it would make me uncomfortable to have a voting procedure in which getting the most out of one's vote required one to begin by figuring out who the two leading candidates were. |
But, of course, this is what we presently
have. There is no requirement that voters make this determination. They can
vote "sincerely," but present systems require that they do so
for one candidate only. The described Approval "strategy" is rational
and allows one easily to determine how to vote under conditions close to the
present. If you don't know who the frontrunners are, you have been living
on some other planet for a very long time. Almost always, they are the
Republican and the Democrat (in the
If you fail to use this strategy, no harm.
That is, no harm over the present method, which forcibly prevents you
from using this strategy – giving you only the choice of either
picking the frontrunner or almost certainly wasting your vote. (With the
asterisk that your wasted vote still might be able to affect ballot position or
public campaign funding next election – which actually distorts the
process.)
Allowing overvoting is the number one
simplest and easiest-to-implement voting reform. All that has to be done is to
delete a few lines in the election code, those that require disregarding ballots
where the voter votes for more candidates than there are allowed winners. I can
see no reason for doing this, except for essentially preventing third parties
from getting any traction. Is this the reason? Perhaps. It may also be that
election process was originally designed without long experience with
elections, and having everyone express first preference was just what they
thought of first. I think there were other proposals before the founding
fathers, though....
And it is my opinion that once voters can
vote Approval, they will then want to be able to express intermediate votes.
Can Mr. Tideman provide us with any reason why they should not be allowed to do
so? His argument above is essentially that they would be harmed if they do it.
Isn't it our prerogative, as voters, to make that determination ourselves?
Indeed, most of the
Range is a ranked method, we should not
forget. Even if one wants to evaluate ballots according to pure preference,
perhaps to determine the Condorcet winner, voters should be free to express the
kind of detailed information that a Range ballot collects. And, of course, once
they are free to express it, we can then begin to understand if preference
strength is important. I have no doubt, however, that it is, and thus pure
preference methods which neglect preference strength are inherently flawed. It
is easy to show
how poor decisions can be made by systems which disregard
preference strength but only consider rank order.