[EM] PR-STV with approval based elimination

Raph Frank raphfrk at gmail.com
Fri May 1 13:54:18 PDT 2009


On Fri, May 1, 2009 at 8:27 PM, Kristofer Munsterhjelm
<km-elmet at broadpark.no> wrote:
> The problem in using any other method than Plurality for counting the votes
> in an STV method is that of elimination. If someone votes for A with
> strength 1 and B with strength 0.5, and A wins, then how much do you
> downweight that voter?

However, it is possible to have 2 different methods of calculation for
eliminations and elections.

In the extreme, you could allow voters to show stronger preferences,
where the voter can equal rank but show slight preferences.

A: 1a
B: 1b
C: 2
D: 3a
E: 3b

would be converted to

A>B>C>D>E

for determining who gets elected.

However, if someone needs to be eliminated, then it becomes

A=B>C>D=E

If either A or B is still running, then the it counts as a full vote
for A and B.

Similarly, if A was elected, and B and C were eliminated, then the
remaining voting strength would be applied to D and E, without a
divide by 2.  (but only for determining eliminations).

This still partially maintains later no harm.  Lower ranked candidates
are ignored, however, the method can still look ahead for slight
preferences.



More information about the Election-Methods mailing list