[EM] Fluffy the Dog and group strategy

Blake Cretney bcretney at postmark.net
Thu Sep 13 17:46:33 PDT 2001

On Thu, 13 Sep 2001 20:28:39 +1000
"Craig Layton" <craigl at froggy.com.au> wrote:

> >> Truly the campaigns can encourage voters to decrease their
support for
> >> Fluffy - enough of this and Fluffy properly loses in Condorcet.
> >> However, Condorcet is in the business of what the voters say, not
> >> they might have said some other day.
> >
> >Well said. As long as the method allows the voters to
> >express their preferences honestly (and feel comfortable
> >doing so), and counts those preferences in a reasonable
> >manner, how can you blame the method for making the choices
> >the voters (collectively) tell it to make?
> Let me leave fluffy aside.  I don't have my original example but
> provide a simple one;
> 49.2% A>B>C (sincere utilities 100>30>0)
> 49.3% C>B>A (sincere utilities 100>30>0)
> 00.5% B>A>C (sincere utilities 100>10>0)

It is confusing that this doesn't add up to 100%.

> When all of the voters have expressed their preferences honestly,
and 99.5%
> would prefer a random dice throw between the three candidates over
> actual result, then I think this indicates that there is a problem
with the
> method.  The fact that this will happen in the best constrained
> voting methods doesn't ameliorate the fact that it is still a
> problem.

If 95% would prefer a random dice throw, perhaps someone should run on
a random dice throw platform, actually intending to throw a die
between the two leads.  This candidate should be the Condorcet winner
in your example, if people behave the way you suggest.  In fact, since
the same argument can be made against plurality, it is interesting
that we don't have such candidates now.

My explanation is that a candidate is always able to create a platform
that combines positions in a way that is more attractive to each side
than the random option.  So, random platforms are unnecessary.

Here's another way to look at it.  You say that 99.5% would prefer a
random result to B.  Now, let's say they knew that random result would
be C.  Now, only a minority would prefer the random outcome.  So, the
original 99.5% was obviously based on ignorance.  You seem to see more
value in a preference if it is based on ignorance.

Blake Cretney

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