Ouch - What I said about IRV missed a bit. Matters little for I still
dislike IRV or Contingent Vote (which I read as running a bit faster
and more often picking the wrong winner).
On Mar 24, 2009, at 10:28 AM, Raph Frank wrote:
On Tue, Mar 24, 2009 at 2:30 AM, Dave Ketchum <[email protected]
> wrote:
Let's try it slowly for IRV, assuming multiple districts to avoid
shortcut
temptations:
1 Count ala Plurality. If leader has a majority, that is winner.
2 Sum vote counts, starting with weakest count and ending before
doing the
next candidate that would make a majority. None of those counted
could win,
so mark them all as losers and go back to step 1.
That isn't true.
The rule is actually that you can eliminate the weakest N candidates
in one step, if the sum of their votes is less than the (N+1)th
weakest candidates. The procedure is then to find the largest
possible N.
40: A
25: B
15: C>E>B
9: D>E>B
7: E>B
4: F>E>B
Round 1:
A: 40
B: 25
C: 15
D: 9
E: 7
F: 4
According to your rules, eliminate F+E+D+C. Eliminating B as well
would cause a majority of votes, so B is safe.
Round 2:
A: 40
B: 60
B wins
However, with full IRV, the results are
eliminat F
Round 2
A: 40
B: 25
C: 15
D: 9
E: 7+4 = 11
F: -
Eliminate D
Round 3
A: 40
B: 25
C: 15
D: -
E: 9+11 = 20
F: -
Eliminate C
Round 3
A: 40
B: 25
C: -
D: -
E: 20+15 = 35
F: -
Eliminate B
OOPS here - The B voters did not name a next rank so 40 A beats 35 E!
DWK
Round 4
A: 40
B: -
C: -
D: -
E: 35+25 = 60
F: -
E wins
So, the result is different.
Less formally, the method is summable if you can "count in
precincts" to
produce managable data chunks that can then be combined to get the
result
for all precincts or districts involved, no matter the size of each
district.
Not clear how this helps. You have to get the totals for round 1
to decide
how to proceed - matters not how many chunks.
I guess IRV is "summable in precincts, subject to central office
instructions".
An election can be verified by checking all the precinct sums/counts
and that the central instructions were correct, assuming that the
precinct sums were also correct.
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