On Fri, 12 Sep 2003, Thomas Richardson wrote:
}[As a side note: Structural equation models can be interpreted as relating
}to individual causal effects - i.e. inferring causes from effects, "Would
}John have a headache had he not drunk coffee this morning given that he
}did drink coffee and does have a headache", but this has not been done by
}econometricians - whereas this is not true of "causal nets".
Pearl gave examples of how to do that if you have another variable P, the
population John comes from. I believe it would go like this:
Coffee --> John_Headache <-- Population
* Set coffee and headache
* Observe new distribution P' (we learned something abt John)
* Unset coffee and headache, and make P' the new prior on P
* Set no coffee
* Observe probability John would have had a headache
- -crt
- --
Charles R. Twardy, Res.Fellow, Monash University, School of CSSE
ctwardy at alumni indiana edu +61(3) 9905 5823 (w) 5146 (fax)
"in much of the rest of the world, rich people live in gated
communities and drink bottled water." --Jared Diamond
