Exact Poisson Regression with Robust Variance in SAS

[ylee12]

Is it possible to fit exact Poisson regression with robust variance in SAS?

[Ksharp]

PROC GENMOD can do Exact Poisson Ression, but not sure if it is Robust Variance.

Or Check RPOC GLIMMIX .

[PGStats]

To me, robust and exact don't belong in the same sentence, but then, what do I know ? Genmod does exact Poisson regression. Countreg (in SAS/ETS) doesn't, but gives you more options to model the variance. Check the Conway-Maxwell-Poisson distribution option.