[EM] IRV vs Plurality
Chris Benham
cbenhamau at yahoo.com.au
Mon Jan 25 20:07:11 PST 2010
Juho wrote (25 Jan 2010):
"I reply to myself since I want to present one possible simple method
that combines Condorcet and added weight to first preferences
(something that IRV offers in its own peculiar way).
Let's add an approval cutoff in the Condorcet ballots. The first
approach could be to accept only winners that have some agreed amount
of approvals. But I'll skip that approach and propose something
softer. A clear approval cutoff sounds too black and white to me
(unless there is already some agreed level of approval that must be
met).
The proposal is simply to add some more strength to opinions that
cross the approval cutoff. Ballot A>B>>C>D would be counted as 1 point
to pairwise comparisons A>B and C>D but some higher number of points
(e.g. 1.5) to comparisons A>C, A>D, B>C and B>D. This would introduce
some approval style strategic opportunities in the method but basic
ranking would stay as sincere as it was. I don't believe the approval
related strategic problems would be as bad in this method as in
Approval itself."
<snip>
The "some higher number of points (e.g. 1.5)" looks arbitrary and results
in the method failing Majority Favourite, never mind Condorcet etc.
51: A>B>>C
41: B>>C>A
08: C>>A>B
B>A 61.5 - 59, B>C 112.5 - 12, A>C 76.5 - 53
51% voted A as their unique favourite and 59% voted A above B, and yet B wins.
Chris Benham
__________________________________________________________________________________
Yahoo!7: Catch-up on your favourite Channel 7 TV shows easily, legally, and for free at PLUS7. www.tv.yahoo..com.au/plus7
More information about the Election-Methods
mailing list