Kevin (and James G-A),
You wrote (Sat.May21):
I don't recall off-hand which "consistency" criteria James has.
They are Monotonicity, Participation and Consistency.
http://fc.antioch.edu/~james_green-armytage/vm/define.htm#continsum
My opinion
of MAPlump and MAppend is that they should be awfully easy to satisfy in most
cases. Monotonicity implies MAppend. MAPlump just says "adding in bullet votes
for the winner can't make him lose."
Looking at "Properties of single-winner election rules," not a single method
that anyone has here proposed fails either of those criteria.
That's not quite true. It isn't the case that any plausible-looking
method easily meets those criteria automatically.
Last year (Thu.Dec.2) James G-A suggested a version of completing
Condorcet by IRV that failed Mono-ad-Plump and Mon-append. It involved
eliminating (dropping from the
ballots) any candidates not in the Smith (or Schwartz?) set and also
any candidates that have a full majority pairwise defeat unless they all
do; and then electing the winner of the IRV
count among the remaining candidates.
http://lists.electorama.com/pipermail/election-methods-electorama.com/2004-December/014275.html
Here is proof from Douglas Woodall. ("AV" is the Alternative Vote, the
UK name for IRV).
>abcd 10
>bcda 6
>c 2
>dcab 5
>
>All the candidates are in the top tier, and the AV winner is a. But
>if you add two extra ballots that plump for a, or append a to the two
>c ballots, then the CNTT becomes {a,b,c}, and if you delete d from all
>the ballots before applying AV then c wins.
Chris Benham
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