comp.soft-sys.sas - The SAS statistics package.
I have used Proc Genmod and Repeated Subject statement to obtain robust standard errors in Poisson and negative binomial regression. Could anyone please tell me something about the STATEMENT AND possible SYNTAX that can be used to obtain robust standard errors in Zero inflated Poisson and Zero inflated negative binomial regression?
For some coef. Estimates, I got ZERO standard error, which causes infty T-values. How could that happen? thank you so much!
Hello, Is it possible to encode in the genmod procedure a ZIP model (zero inflated poisson model) or did some one write a macro to do this ? Benoit Maris
I'd recommend to use the proc means command before starting. You may have something suspicious going on with your explanatory variables. But it's hard to say without knowing more about the DGP. God Jul o Gott Nytt Ar! Tomas On 12/22/06, Wensui Liu < XXXX@XXXXX.COM > wrote: > > For some coef. Estimates, I got ZERO standard error, which causes > infty T-values. How could that happen? > > thank you so much! >