[EM] Does the 'Independence of Irrelevant Alternatives Criterion' Imply a

[Forest Simmons]

On Thu, 1 Apr 2004, James Green-Armytage wrote:

> Forest Simmons <fsimmons at pcc.edu> writes:
> >To make this really simple, suppose that there is only one chooser, and
> >that there are three choices, and that the chooser prefers A to B to C to
> >A, with varying levels of intensity.  Suppose that the chooser finally
> >decides to choose A.  But before announcing her decision she finds out
> >that option B has been withdrawn.  Is she going to stick with A?
> >
> >In other words, not even a dictator method can satisfy the IIAC at the
> >fundamental level of actual preferences.
>
> 	I have to say that I don't think it makes sense for an individual to
> prefer A to B, B to C, and C to A. It's just logically contradictory.

Who said that individuals are logical?  Couldn't a dictator be
schizophrenic?

> Individual preferences should be assumed to be transitive.

If you look up the recent thread on the neural network approach to
democracy, you will see that not all list members subscribe to your
transitive preference axiom.

It's perfectly possible for a brain to be wired or programmed by genetics
or experience so that someone prefers red to green, green to blue, and
blue to red.  To over simplify, suppose that two thirds of your neurons
prefer red to green, a different two thirds of your neurons prefer green
to blue, and yet a different two thirds of your neurons prefer blue to
red.

Human individuals are composites, not atoms.

Your axiom might be a useful approximation to reality, but like most
axioms, it isn't an absolute truth.

Forest