On Jan 20, 2010, at 12:48 PM, Chris Benham wrote:
Dave Ketchum wrote (18 Jan 2010):
"In response I will pick on LNH for not being a serious reason for
rejecting Condorcet - that such failure can occur with reasonable
voting choices for which the voter knows what is happening. Quoting
from Wikipedia:
For example in an election conducted using the Condorcet compliant
method Ranked pairs the following votes are cast:
49: A
25: B
26: C>B
B is preferred to A by 51 votes to 49 votes. A is preferred to C by
49 votes to 26 votes. C is preferred to B by 26 votes to 25 votes.
There is no Condorcet winner and B is the Ranked pairs winner.
Suppose the 25 B voters give an additional preference to their
second choice C.
The votes are now:
49: A
25: B>C
26: C>B
C is preferred to A by 51 votes to 49 votes. C is preferred to B by
26 votes to 25 votes. B is preferred to A by 51 votes to 49 votes.
C is now the Condorcet winner and therefore the Ranked pairs winner.
By giving a second preference to candidate C the 25 B voters have
caused their first choice to be defeated.
Pro-A is about equal strength with anti-A. For this it makes sense
for anti-A to give their side the best odds with the second vote
pattern, not caring about LNH (B and C may compete with each other,
but clearly care more about trouncing A)."
<snip>
Dave,
Your assumption that "B and C may compete with each other, but
clearly
care more about trouncing A" is based on what?
That one faction votes ONLY for A, and the other faction votes
exclusively against A. Then some anti-As vote for both B and C. The
B voters considering voting for B>C is consistent with this.
The ballots referred to contain only the voters' rankings, with no
indications
about their relative preference strengths.
The voting implies strength of preference.
If you read my entire post you will see that in it I endorse three
methods,
one of which is a Condorcet method.
This starts with my dislike for IRV, which started with my first
hearing of that method and immediately liking Condorcet as better -
before having heard of either method name. From that have to reject
LNHarm for incompatibility - and thus respond to your liking of LNH.
Dave Ketchum
Chris Benham
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