[EM] Condorcet Violates Strong FBC

[Forest Simmons]

Random ballot does satisfy strong FBC.

I suspect that no majoritarian method absolutely satisfies strong FBC,
though some methods like the instant version of CRAB (Cumulative Repeated
Approval Balloting) satisfy it for all practical purposes.

I'll write more when my Internet Service Provider quits acting up.

Forest




On Mon, 4 Nov 2002, Alex Small wrote:

> Elisabeth Varin/Stephane Rouillon said:
> > Alex,
> > does any method satisfy strong FBC?
>
> Good question.  I know that Condorcet methods don't, and monotonic
> majoritarian methods don't.  Rated methods don't.  If I could show that
> majoritarian methods don't, irrespective of montonicity, I'd be
> satisfied.  We know that IRV is non-monotonic but majoritarian, but it
> doesn't satisfy strong FBC.  Maybe I need different techniques.
>
> I started looking at the case where we remove monotonicity.  You have to
> consider the possibility that favorite betrayal gives the same result as
> a voter changing his preference from A>B>C to A>C>B.  Then you have a
> new electorate.  But then you have to look at the new electorate and try
> to figure out which faction to tinker with.  The number of scenarios to
> consider grows out of control.  If I can just find a path out of that,
> one that takes me in a circle to expose a contradiction, I'll be happy.
>
> Any thoughts on extending the current results to 4 or more candidates?
>
>
>
> Alex
>
>
>
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