On Nov 9, 2009, at 1:46 AM, Jonathan Lundell wrote:
On Nov 8, 2009, at 10:40 PM, robert bristow-johnson wrote:
On Nov 8, 2009, at 7:50 PM, Jonathan Lundell wrote:
On Nov 8, 2009, at 4:35 PM, Warren Smith wrote:
Tideman said IRV was unsupportable if it is feasible to compute
pairwise matrix. That was
because Tideman had other voting methods he considered clearly
superior to IRV and these methods used the pairwise matrix. By
"clearly superior" I mean, so superior in every respect, that
Tideman
felt there was no conceivable use for IRV, ever (in situations
where
it was feasible to compute pariwise matrix) where that use could be
"supported."
That is what "unsupportable" means.
Tideman ranks IRV highest in resistance to strategy, and
generally better than the pairwise methods in lucidity
can someone explain to this layman what the metric "lucidity" is
in regard to election methods?
Generally speaking, the degree to which a method is understandable
by voters.
then i think that "the pairwise methods" (i presume Condorcet) is
getting a bad rap, particularly compared to IRV. Condorcet is simple
conceptually (save for what to do in case of a cycle). dealing with
a cycle can be a mess, but if there is no cycle, executing the
Condorcet tally is a piece of cake. any C programmer can punch that
program out in a half hour.
and i think that tactical or strategic voting is most commonly a
result of voter regret. usually the tactic is "compromising" because
some Nader voters in Florida figgered out that in 2000 they just
helped put the worst and most illegitimate person in U.S. history
into the Oval Office and decided to vote for Kerry (even though they
don't like him) the next time around (2004). "compromising" is the
tactical insincere vote that is most prevalent, in my opinion. i've
seen first-hand how IRV will make some Republicans think twice
(assuming IRV survives the referendum) about voting for their
candidate as their first pick, because they found out that doing so
actually elected their least favorite candidate (the Prog) over the
more centrist candidate (the Dem, whom more would prefer over the
Prog). that would not have happened with Condorcet in that example.
i really don't see IRV as more resistant to tactical voting in regard
to the most common tactic of compromising.
and cost of computation.
and why the cost of computation (as if it takes the official
computers 10 seconds to crunch the numbers instead of 5) is
important in modern times? it's not like the cost is O(2^N) or or
O(N!).
It's relevant in two ways, I think. One is wrt hand counting.
it increases the cost of hand counting by a factor of M*(M-1)/2 if M
is the number of candidates.
The other is actual computational complexity. I don't think that
any of the methods on Tideman's FPTP-replacement list are complex
in that sense, but there are certainly proposed systems (including
Tideman's own elaboration of PR-STV) that appear to be impractical
to compute with current technology and algorithms, in some cases.
the number of pairs in Condorcet is M*(M-1)/2 for M candidates. your
computer runs M*(M-1)/2 hypothetical traditional elections for each
pair. once the physical ballots are recorded, it's a line of data in
a file (the optical scan or punch cards need not be processed
again). if there are N voters, the cost is N*M*(M-1)/2. it's
proportional to the big number (the number of voters). the number of
candidates is small (is M ever bigger than 6 or 8?) i cannot see the
computational cost of Condorcet as anything approaching prohibitive,
even for a national election with a dozen candidates.
--
r b-j [email protected]
"Imagination is more important than knowledge."
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