At 02:31 PM 1/8/2013, robert bristow-johnson wrote:
On 1/8/13 1:03 PM, Warren Smith wrote:
So should this realization by Jameson Quinn tell us that all
previous historical
examples of Bucklin voting should be regarded as examples of the
"Majority-Judgment" median-based system,
and hence can be used to help evaluate how the latter behaves in practice?
Unfortunately I think not because I think Bucklin voters historically
were urged to provide rank-orderings not ratings.
well, isn't that how it works for Bucklin? the inclusion of the
2nd-choice or 3rd-choice votes in the total vote count is a sorta
discrete decision. then only inequalities exist for the decisions
made by Bucklin. if that's the case, the only information that
matters in rating candidates are the relative ranks.
i dunno.
Equal ranking in classic Bucklin was allowed in the third rank. It's
a bit of a mystery why they did not allow it in the first two ranks,
but I suspect it was merely to make it more familiar to people
accustomed simply to "vote for your favorite." The third rank equal
ranking possibility made the system even more clearly an Approval
system, and when there were many candidates, it was common for the
ranks to be completely collapsed, so it really did end up as an
Approval election, with the standard Approval phenomenon of candidate
totals exceeding the number of voters.
It was also allowed to skip ranks. That is characteristic of Range,
and not of ranked systems, and the meaning of a skipped rank in
Bucklin is quite the same as skipped ratings in Range: it indicates a
stronger gap in preference strength.
Bucklin really was Instant Runoff Approval, quite the same as a
simulated series of Approval elections (but, unlike a real series of
elections, voters in subsequent rounds have, with plurality-electing
Bucklin, no additional information. They are guessing, more or less.)
Imagine that voters have a range-ballot-in-mind, and are with each
round, lowering the approval cutoff a bit.
Voting reform in the U.S. has neglected Bucklin, to its cost.
And voting systems experts have frequently neglected Top-Two runoff,
the most widely-implemented voting reform. TTR has some obvious
flaws, but the *concept* of iterated voting has tremendous power. The
flaws can easily be fixed by using a more sophisticated primary
system, and with a better ballot, a runoff, if needed, could handle
two candidates plus write-ins, without a spoiler effect there. With
improved ballot analysis, which could still be simple, a runoff
system could be made Condorcet compliant *and* SU optimizing.
That last one has been controversial, but it works by testing
absolute preferences with a runoff. Low absolute preference
difference between runoff candidates equals low turnout from those
with low preference. When there is a pairwise beaten Range winner,
the preference strength is necessarily low for that pairwise winner
(otherwise this would be the Range winner!).
Real runoffs produce "comeback elections," in about one-third of the
cases (for nonpartisan elections), where the runner-up in the primary
wins the runoff. Runoff electorate is not the same as primary
electorate, in addition to vote transfers. (In non partisan
elections, simple vote transfers will generally not shift relative
position; that is why IRV fails to produce this comeback effect in
nonpartisan elections. It does only in partisan elections, where vote
transfers are strongly correlated with the first preference.)
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