Re: Ecological Fallacy?

[Bernard L Cohen <blc+@pitt.edu>]

	For applications to radiation health effects, the "ecological
fallacy" is to assume that, for large groups of
individuals, the average dose determines the average risk. This is
obviously a fallacy for a dose-response relationship characterized by a
threshold -- the population exposed below the threshold does not
contribute to the risk but it does contribute to the average dose.
	However, for a linear-no threshold dose-response relationship, it
is easy to show that the ecological fallacy does not apply; the average
dose does determine the average risk. This is familiar to Health
Physicists from the fact that person-rem determines the number of deaths;
person-rem divided by the population is the average dose, and the number
of deaths divided by the population determines the risk of death.

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Wed, 25 Feb 1998, Sorensen, Scott wrote:

> RadSafers,  
> 
> I've been reading with interest the thread regarding radon epidemiology
> and its implication to the LNT theory.  Not being one intimately
> familiar with the science, could anyone post a description and describe
> the implications of "ecological fallacies?"
> 
> Thx,
> Scott Sorensen
> ssorensen@doeal.gov 
>