The family of "regular" probabilistic (stochastic) electoral systems

[David Catchpole]

On Wed, 8 Dec 1999 DEMOREP1 at aol.com wrote:

> s349436 at student.uq.edu.au wrote in part--
> 
> Okay- "Regularity" is the name used earlier by Albert Langer (Craig might
> recognise the name ;) ) to describe the probabilistic analogue of IIA. It
> goes like this-
> 
> The addition (removal) of a candidate does not, for any other candidate, 
> increase (decrease) the probability of that other candidate winning.
> ---
> D-
> A simple example-
> 
> 2 A>B>C
> 1 C>B>A
> 

well, without C: p(A)=2/3, p(B)=1/3
without B: p(A)=2/3, p(C)=1/3
without A: p(B)=2/3, p(C)=1/3

So an answer where A,B, and C all run and  regularity (at least for the
cases we know) holds is, say p(A)=2/3, p(C)=1/3

> Guess what happens if candidates are added or removed.
> See the earlier postings regarding clones and circular ties.
> 
> 

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