On Dec 1, 2008, at 10:31 AM, Abd ul-Rahman Lomax wrote:
At 12:54 AM 11/26/2008, Jonathan Lundell wrote: [attribution
corrected]
My own view is first that we're talking about marginal differences
here, and that PR vs single-winner elections is of much, much greater
interest, and second that the interesting difference between
plurality, IRV and other ranked methods is not in how they count
any particular profile, but rather in how they influence candidate
and voter behavior. In the IRV examples that Greg and Abd adduce,
we don't actually know what the ballots would have looked like if
the elections had used plurality. The set of candidates might well
have been different, the nature of the campaigns different, and
voter strategies different.
That's correct. We can make some reasonable assumptions, though. We
can look at Plurality elections and look at how many voters vote for
minor candidates with no hope of winning. We can then look at IRV
results and convert comparable percentages of these votes to
plurality votes for frontrunners. I think we could get pretty close.
That, it seems to me, requires a leap of faith, or at least making
assumptions that are hard to find objective verification for.
Campaigns, from experience, don't seem to be much different. Voter
turnout doesn't seem to be much improved with IRV, though,
theoretically, it should improve turnout a little.
An exception is the second round of a TTR election. San Francisco is a
case in point, and I'm guessing fairly typical, in having very poor
turnout for their second round, less than half the first round, IIRC.
This would be an advantage of any single-round method over TTR, of
course.
The fact, however, that the sincere preferences expressed by voters
for minor candidates don't shift results, in nearly all cases, acts
contrary to this effect, in the long run. So you get to vote
"sincerely," but with no net effect? You can "vote" more sincerely
by giving a campaign donation to a minor candidate!
My sense is that minor parties are optimistic that a) they'd
demonstrate a higher first-round vote with IRV than plurality in any
given election, and b) that the improved showing would have a
beneficial effect on future elections. That is, the benefit of IRV
(and again this wouldn't be exclusive to IRV) extends beyond any
single election.
Is that true? I don't know, but there's some reason to think so. Green
Party candidates running "real" campaigns have typically been able to
obtain about 10% of the vote in California state assembly elections in
recent years. Suppose they could reach 15-20% of the IRV first choice.
That would give major-party candidates significantly more incentive to
appeal to those Green voters for their second choice.
Voter strategies in Plurality are based on main considerations:
(1) Vote for the favorite. This actually works, it's better than one
might think. It is *highly* likely to produce the same winner as a
more advanced method, and it is only under special conditions that
it fails. So a lot of voters do this. Note that, by definition, most
voters, voting this way, are voting for a frontrunner, so this
"sincere" strategy is the same as consideration 2.
(2) Vote for the preferred frontrunner, because all other votes are
moot. This is only important for minor party supporters who want to
express that for some other purpose than winning an election, such
as ballot position. Or for purely personal reasons, such as being
pissed at a party for not nominating their favorite, who is running,
and they either think that the possibility of the candidate from the
opposing part won't win in any case, or they don't care. Damn them
all! Yes, some voters vote like this, God bless them. It's part of
the system. Don't unnecessarily piss people off, make sure they see
the process as fair, if possible. Not always possible.
Which of these strategies the voter actually uses depends on
preference strength. Tricky to estimate, but, again, I think that by
studying average behavior, we could get close.
Essentially, we can look at IRV results and predict, probably within
a few percent, what the Plurality vote would have been. Most voters
probably use strategy 2 in Plurality; Plurality also tends to
suppress minor party candidacies which, with Plurality, show far
lower than the real party support, because of the strategic voting.
One of the benefits of Range, Warren calls it the "incubator
effect," is that a measure of third party support becomes available,
and there is little reason to assume that this would be insincere.
Why bother voting an "insincere" rating for a non-viable candidate?
Given that the vote has about zero chance of influencing the
outcome, in most elections.
(But if you prefer a major candidate, it could be foolish, with
Range, to max rate a minor candidate. It doesn't accurately
represent your preferences, but for no good strategic purpose. Only
if you fear that the minor candidate might be the runner-up, and
lose to someone worse, would you do that, and this means that you
don't think this is a minor candidate. This might be a winner. I've
said this many times: if you would seriously regret a Range Vote,
under any reasonable scenario, including some election surprise --
like Le Pen getting second place -- don't vote that way. Adjust your
vote so it is safer. The Le Pen result was not expected, to be sure,
but those French elections, with many candidates, were very
susceptible to small variations. Had it been a Range election in the
primary, Le Pen wouldn't have made it to the runoff, I'm sure.
*Maybe* Range would have detected Jospin, maybe not. With "sincere"
Range votes, sure. But the Range winner, with no runoff, would
almost certainly have been Jospin. Note that IRV could easily have
missed Jospin, for the same reason that the plurality primary missed
him. Jospin would have, with even higher certainty, in a majority -
required Range election, been in a runoff against, again with high
certainty, with Chirac, and would have won.)
(FairVote, to criticize Range, posits a truly preposterous election
scenario, where voters prefer one candidate over another, and 99%
vote 100 for the favorite and 99 for the other. A very small set of
voters (1 or 1% in the example) vote 0 for the first and 100 for the
second, and, of course, this outweighs the preference of a huge
majority. But it is an extraordinarily weak preference, and if it
was accurate, all voters will be very satisfied with this outcome,
and they will not be saying "damn! I wish I'd voted like that
selfish voter!" They will be, instead, if this is a real election,
and there were other candidates who might have won, with
significantly lower preference, very happy with the outcome and they
will all go out and party together. In other words, FairVote wants
us to think that the violation of the Majority Criterion is a Bad
Thing, when, in fact, the outcome is very good, better than I have
*ever* seen in a public election. If that majority would regret its
supposedly "sincere" vote, why in the world did they vote that way,
effectively abstaining from an important pairwise election. Surely
the exaggerated their real preference toward the top. That is an
error in voting, and errors in voting can always produce poor
results! In a real election, how likely is this error?)
(We have 99% of the voters apparently thinking that there is a risk
that their favorite will lose, not to the second candidate, the 99,
but to someone much worse. However, in fact, there are *no* voters
who prefer the third candidate. If there is no third candidate --
FairVote doesn't specify -- then what we have is a situation where
the 99% majority essentially said, well, we have a tiny preference
for one candidate, but, really, don't listen to us unless the rest
of you really don't care. So they voted with votes of 1/100 vote
value in a binary election. Why? Only if they really don't care,
this is *almost* like a voter abstaining. Indeed, it's an almost
total abstention on the part of the voters. This vote is based on
the idea that voters are supposed to vote sincere absolute
utilities, though in this case, the utilities were normalized at the
top but not at the bottom. So the 99% may have been saying, I have a
*significant* preference for A over B, but because both A and B are
not Genghis Khan or Adolf Hitler, I'd have to be pretty grateful for
the election of either, so, to be honest with you, my preference for
A over B is only 1% -- tiny -- of my preference for B over C. I'd
die to prevent C from being elected. C isn't on the ballot? That's
irrelevant, I'm voting my "sincere utilities" because someone told
me this was better. And if they believed that, I can get rich, I can
sell them deeds to famous bridges. Voting is a choice, not a
sentiment. If this is a binary election, you are being asked to make
a "sincere choice," not make a "sincere rating." You can rate
"sincerely" if want, but if you don't want to waste your vote, you
will have to normalize your vote to the candidate set at the bottom,
too. Which would imply voting min for B, if there are only two
candidate. Voters *can* vote as described, but, then, it *clearly*
is based on a desire to abstain. These are votes, expressed in
fractions of a vote, multiples of 1/100 vote, they are *not*
sentiments. If you care about the outcome, show it!)
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