[R-sig-eco] Offsets in Poisson or Neg. Bin regression

[Ivailo]

On Tue, Jun 18, 2013 at 11:10 AM, Matias Ledesma <matutetote at hotmail.com> wrote:
>
>
> Philip and Alain,
>
> Thank you for your assistence,
> So, that mean that the  fuction offset its only possible if there is a relationship between the
> damaged number of embryos and the total number of embryos per amphipod as you explained?

As I'm facing a similar problem, I'd like to know as well if a
variable should be passed as an offset to the formula only when it
influences the outcome in some (linear) way. Does it make sense to
include the exposure variable in the model as a regular input first,
and if it's coefficient is around 1 to be taken as an indicator that
it is better that variable to be included in the model as an offset?

Cheers,
Ivailo
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UBUNTU: a person is a person through other persons.