At 01:57 PM 1/10/2010, Stéphane Rouillon wrote:
Abd Ul,
from the data you produce, I agree that for the
Burlington election, IRV did produce the same result
FPTP would have produced.
However, nobody can generalize this perticular case to any election.
Stephane, we now have much data on nonpartisan
elections using IRV in the U.S. I think you've
misunderstood my position. I'm not generalizing,
I'm reporting what actually happens, and only
from that, generalizing as a prediction, not as
some kind of rule. There is no rule. It is
possible for a comeback election to exist with
IRV even in nonpartisan elections, but it seems to be, at least, very rare.
I agree that in non-partisan election the
rallying pattern of defeated voters does not fit
only one typical set of preferences.
However again, a statistical analysis of general
preferences shows an unbalance of preferences, even for non-partisan elections.
There is *some* "imbalance." I.e., those who
prefer A are *somewhat* different from those who
do not, as to B>C preference ratios. But that
imbalance isn't strong, it is quite weak.
Is this unbalance major to the point that IRV
could allow a come-back from another candidate than the plurality winner, or
is this unbalance minor so IRV does not change
anything, it depends of each election.
Of course. Except that across many elections, we
simply aren't seeing the "simulated comeback elections."
On a last aspect, I do agree that Condorcet is
better than both. And I admit that , even if I believe that the distribution
of a generalized set of preferences is
unbalanced, I have not yet been able to evaluate or quantify this unbalance.
I think you are trying to swim upstream.... the
general rule with nonpartisan elections seems to
be what I've said, that is, *more often than
not*, or *as a rough estimate*, the voters are a
sample of a relatively homogenous population that
happens to differ in a particular characteristic:
their first preference. The second and lower
preferences are *relatively* independent of the first preference.
Really, this is a quite remarkable finding!
You can argue that as long that I was not able
to quantify by how much this unbalance occurs
(amplitude distribution), it is not
acceptable to claim that this unbalance should
allow IRV to find a "better" winner.
My strong suspicion is that Plurality *usually*
works well in nonpartisan elections, because of
the effect I'm reporting. There are exceptions,
for sure. By no means do I consider this avenue
of approach to be fully explored! The election
which was the basis for Brown v. Smallwood, the
Minnesota Supreme Court case that ruled Bucklin
voting to be unlawful there, had Brown with a
plurality of first-choice preferences. But
Smallwood won, by a good margin, after additional
preferences were added in. Without actual ballot
data, we don't know what would have happened with
IRV, though, that reminds me, I should look at
the data again. What if it had been batch
elimination IRV? That kind of analysis might be
applicable to the Bucklin results....
When there are *many* candidates, most methods
tend to break down, unless a true majority is
required. That, in fact, is the basis of the most
advanced voting system in common use, to my
knowledge: repeated voting, vote for one, no
eliminations but only voluntary withdrawals or
new nominations. Until a majority winner appears.
If this weren't in common use, I can imagine
voting systems experts complaining that it could
take forever. But it does not actually take
forever, the voters finally figure out that they
have to make some compromises or else they aren't
going to get to go home. They used to, in some
organizations (like the Catholic church for papal
elections, perhaps, or the Doge election in
Venice, force the electors to stay in the room
until they emerged with a decision. I think the
papal elections required a two-thirds vote, and
approval voting was used. The Venetians also used
approval voting; approval is quite an efficient
method if used for repeated balloting, and
Bucklin simulates it to some extent.)
But, we do have data of previous elections and
because we both agree that a Condorcet winner is
a "better" winner for this purpose, we can use this reference to evaluate the
combined impact of IRV and the unbalance of the
preference sets. Thus, even if I do dot know the
general unbalance distribution,
I can observe that IRV allows more often to
obtain a Condoret winner when plurality fails,
than plurality finds a Condorcet winner
when IRV fails. So I claim IRV is more reliable than plurality.
What election data are you referring to?
The serious complication here, in comparing
Plurality with a ranked ballot method, is that
candidate behavior and voter behavior are
seriously different if there is a single-ballot
plurality election, than with the other methods.
When I suggest that plurality might be a better
method than we often think from theoretical
considerations and simulations, it is due to this
other behavior, which causes many voters to make
the necessary compromises to gain the result
they, after all consideration, prefer from among
those they consider possible outcomes.
We cannot predict Plurality votes from IRV or
other ranked system votes. I've claimed that
there is some reasonable level of predictive
power between IRV, Bucklin, and Condorcet method
voting, because these methods do encourage
sincere expression of preferences. In the case of
IRV, in particular, that encouragement is based
on a false promise, but I don't expect that
knowledge of this has spread sufficiently to
seriously compromise voting behavior. It will, if the use of IRV continues.
But, I suspect, Burlington may drop IRV. And I
wouldn't expect to find much voting pathology in
nonpartisan elections, not that is visible from
the ballots. The damage IRV does in replacing top
two runoff, in nonpartisan elections, is that the
increased scrutiny of a runoff is missing. Thus
Ed Jew was elected with less than 40% support in
San Francisco (was that 2004?). And it then
turned out that he didn't live in the district,
he was an illegal candidate. In a runoff election, this would have been seen.
Unfortunately, San Francisco, just before it
implemented IRV, outlawed write-in votes in
runoff elections, a serious blow to democracy,
supported by a poor decision by the California
Supreme Court. Voting systems activists seem to
have been completely asleep when this took place,
in 2002, I think it was. That's because of the
serious lack of attention to top two runoff as a
voting reform among voting systems theorists, who
have mostly ignored the method, which is, except
for the center squeeze problem which is easily
fixed, quite an advanced method, much better than
simple-minded simulations show.
It's the effect of voter turnout on overall voter
satisfaction with results! -- i.e., true Bayesian
regret, considering the entire electorate, not
just those who actually cast ballots. The voters
are a biased sample of the entire electorate,
biased toward, in a special election, stronger
preference. Which then causes the results to
shift toward minimized Bayesian regret.
To fix the Center Squeeze problem, simply use
Bucklin for the first round; continue to require
a majority, don't accept a plurality Bucklin
winner, but hold a runoff. Perhaps the top two
Bucklin vote-getters would be on the runoff
ballot. If write-ins are allowed, and Bucklin is
used in the runoff, there is no spoiler effect in
the runoff, a write-in is at worst harmless.
And to get better than this, we'd need to use
Range methods, to allow voters to directly
express preference strength. My suspicion is that
the most truly ideal method we could use would
involve a Range ballot with explicit approval
cutoff, and a runoff when needed. I'll leave
"when needed" not clearly defined yet, it could get quite sophisticated.
And to move even further beyond that: Asset
voting, which allows purely deliberative
approaches to single-winner elections, and could
allow rapid recall and other desirable features.
(Note that recall has its own problems, but it
should be up to the chosen representatives of the
electorate to determine when it's truly
appropriate. If we are considering elections of
legislative representatives, they should be
*representative*. They aren't judges or the kind
of leaders or officers who should be insulated
from a need for public support. They should be
actual leaders and actually responsive to their
constituents. Asset allows the creation of a
representative assembly that is truly and
completely representative, to the maximum degree
possible, and even beyond that, to *total
representation* in some respects. No wasted votes. Not one.
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