Irrelevant Vs. Clone (was RE: [EM] IRV in San Francisco)

Paul Kislanko kislanko at
Tue Nov 16 15:14:58 PST 2004

YES! That's what I didn't have the right words to say. ICC is a subset of
IIA is what I meant by "ICC is a weaker formulation of IIA". Something can
satisfy ICC but not satisfy IIA. 

The original question was how to define the word "spoiler", and I've come to
the conclusion that it cannot be used at all without some qualification. An
"IRV-spoiler" might be a clone or it might be an IA, and it can be one
without being both.

> -----Original Message-----
> From: at 
> [ at
> ] On Behalf Of bql at
> Sent: Tuesday, November 16, 2004 5:02 PM
> To: at
> Subject: Irrelevant Vs. Clone (was RE: [EM] IRV in San Francisco)
> In a method that mistreats clones, a clone is an "irrelevant 
> alternative". 
> Dropping a non-winning clone, allowing the other non-winning 
> clone to win, 
> violates the desired independence of irrelevant alternatives.
> Thus, everything that violates the clone criterion, violates 
> independence 
> of irrelevant alternatives. I think that makes ICC a subset of IIA.
> Brian Olson
> ----
> Election-methods mailing list - see 
> for list info

More information about the Election-Methods mailing list