Various factors that affect real elections have been neglected in the
simulations which have been done to compare performance of various
voting systems. The analysis which has been done, so far, is quite
valuable and represents the best data we have on voting system
performance, but the neglect of real voting patterns and factors has,
I suspect, produced warped comparisons of systems.
The technique of simulating underlying absolute preferences has too
quickly moved into an assumption that preferences can be normalized
and that all members of the simulated population will actually vote.
In fact, real voter behavior can be predicted to vary with preference strength.
As an example, if I'm correct, analysis of Bucklin made the
assumption that all voters would rank all candidates, which is
actually preposterous
Further, with Top Two Runoff, a assumption has been made that all of
the original voters will then vote in a runoff, so the simulation, of
course, simulates a Contingent Vote that accomplishes the same thing
with a single ballot, unless, of course, voters truncate, and
truncation hasn't been simulated, to my knowledge.
In fact, voters with low preference will not turn out to vote in a
special election runoff. If the system is implemented with the
primary as a special election (as in Cary, NC) and the runoff in the
general election, then we'll see the effect of low preference
strength on turnout in the primary instead.
It is a common assumption that low turnout in an election is a Bad
Thing. However, I've seen little analysis that does anything more
than make partisan assumptions; allegedly, low turnout favors
Republican candidates. If so, then the source of the problem would be
large numbers of voters who might otherwise favor a Democrat, but who
have, in fact, low absolute preference strength, and Baysian regret
analysis of the whole population would likely reveal that the
Republican would be the social utility winner.
Turnout differential shifts any voting system toward social utility
optimization and away from majority, plurality, or Condorcet
criteria. Overlooking this has caused voting systems theorists to
overlook the power of runoff systems, which have been assumed to be
mere technical methods.
In fact, runoffs have not only this value, but the values noted by
Robert's Rules of Order for repeated ballot in general. (Robert's
Rules does not support "runoffs," i.e., elections with
rigidly-determined candidate eliminations, it requires repeated
elections, in toto, if there is a failure to find a majority of all
those voting in the election, accepting the winner.)
Those values are: the ability of the voters to make decisions,
including compromises, based on the results of the first ballot, and,
as well, to make more informed decisions based on better knowledge of
the candidates. We know that real runoff elections, nonpartisan, do
produce "comeback" elections in about one-third of the cases. This
phenomenon does not happen with Instant Runoff Voting, so the
instantaneous preference profiles of voters in the primary are not
simply replicated in the runoff, or, at least, that is the most
likely explanation. There is also truncation as an explanation.
Some study of Bucklin has been based on an assumption that
Later-No-Harm is important to voters. It's clearly important to
*some* voters, specifically the most partisan. A partisan Democrat is
not likely to add a second-rank vote for Bush in a Bush v. Gore
election. But an independent voter *might*. And more to the point, if
the voter buys the Tweedle-dum and Tweedle-dee argument of a
candidate like Nader, they might well not cast any second-rank vote
at all, even if they have some preference for one candidate over another.
We know, however, that in nonpartisan elections, the addition of
additional ranked candidates was reasonably common in actual Bucklin
elections. However, there is a basic voting phenomenon which has been
inadequately considered, even though it was first noted, to my
knowledge, by Charles Dodgson (Lewis Carroll) in about 1883. Many or
most voters only have a good idea of their first preference, and, in
an STV system, may be likely to truncate below that, and bullet
voting, or at least some level of truncation, makes sense as a
sincere vote for such a voter.
Out of some idea that "majority" is important, but not understanding
the *purpose* of seeking a majority, some places and some theorists
have advocated mandatory full ranking, which is combined, in
Australia, with mandatory voting. It's illegal not to vote there, and
if a ballot is cast (except in places which have Optional
Preferential Voting), and does not fully rank the candidates, the
ballot is "informal" or discarded.
Majority failure is an essential feature of single-ballot systems,
all of them, it will occur with some considerable frequency, unless
the "majority" is in some way coerced, or the options are limited to
two, which also frustrates democratic purposes.
Hence repeated ballot is ideal, and only deprecated for reasons of
expense and efficiency. The question then becomes, once we realize
this, *how much damage is done in the name of efficiency?*
If the damage is trivial, it's not really a problem. But if the
damage is major, and it can be, then to avoid runoff elections in the
name of saving money and "trouble," is penny-wise and pound-foolish.
Rather, the question would become how to *avoid* runoffs when
sufficient data can be collected from voters to make the runoff
redundant and unnecessary. And there has been far too little study of
this problem. Robert's Rules suggests preferential voting as a way to
reduce the need for repeated ballot, and certainly considers it an
improvement over accepting a plurality result, but apparently does
not realize that the sequential elimination method that they describe
is singularly inefficient at the goal of actually finding a majority
of votes, but in no way are they deluded into thinking that the "last
round majority" of IRV is a real majority, it obviously is not, and
Robert's Rules requires that the election be repeated if a real
majority of votes is not found.
Bucklin is quite a bit more efficient, because it counts all the
votes. It's been argued that counting all the votes, as Bucklin will
have done in any situation that is at or is approaching majority
failure, will cause voters concerned about Later-No-Harm to
truncation, and that's true, but only to a degree. It depends on the
preference strength of the voters for their favorite over all
alternatives. Thus the additional preferences that voters express in
Bucklin are, in fact, sincere additional approvals, assuming
reasonably educated voters. When Bucklin finds a majority, it is a
true majority of voters accepting that result.
Further, selective truncation based on preference strength, quite
likely, shifts real Bucklin results toward Range results, since low
preference strength votes are suppressed.
From these arguments, I suspect that in real social utility
performance, Bucklin with a majority required, used in a primary,
with plurality Bucklin reserved for runoffs (where it can be two-rank
Bucklin), is very close to ideal, but this does, as well, depend on
details of Bucklin which have sometimes been missed.
As an example of an important detail, some real and notable Bucklin
implementations allowed multiple voting in the third rank. Thus the
method was a closer implementation of Approval voting than has been
realized. One really could vote this kind of Bucklin as an
antiplurality, "anybody but Joe" method. An obvious improvement on
the old Bucklin, then, would be to allow equal ranking in all ranks.
It's not terribly important, overall, that equal ranking be allowed
in the first two ranks, but it would allow better and more accurate
expression by voters, as well as providing some safety net for the
unusual situations where strategic voting in Bucklin could suggest
preference reversal. Instead of reversal, what can be done is to vote
equal rank, which is less harmful and more sincere. ("Equal" means
"to be equally supported under the voter's understanding of election
conditions." It does not mean that there is no preference, but that
the preference is small compared to other issues, most particularly a
strong dislike of some frontrunner. I actually think this condition
would be so rare that I'm not stressed about the idea that equal
ranking might continue to be disallowed in the first two ranks, but
it's important, if Bucklin is to handle large candidate sets, that it
be allowed in third rank.)
Bucklin with equal ranking thus becomes quite a close approximation
of Range voting, and could even be implemented using a Range ballot,
as long as approval cutoff is specified. In combination with runoff
requirements when there is failure to obtain majority approval, most
realistic election pathologies can be avoided. Bucklin is alleged to
violate the Condorcet Criterion, but, in fact, it only does so, I
consider likely, under conditions where the Condorcet Criterion fails
to find an optimal winner but merely pretends to, based on an
assumption that all preferences are equal.
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