Did you accidentally put a comma before the if statement?
. sysuse auto
(1978 Automobile Data)
. nbreg rep mpg ,if fore == 0
option if not allowed
r(198);
. nbreg rep mpg if fore == 0
Fitting Poisson model:
<snip>
Scott
> -----Original Message-----
> From: [email protected] [mailto:owner-
> [email protected]] On Behalf Of sarah smith
> Sent: Monday, March 14, 2005 2:37 PM
> To: [email protected]
> Subject: st: how to run nbreg with "if" command?
>
> Dear stata users;
>
> I am trying to run nbreg as below;
>
> nbreg y x1 x2 if x3==1
>
> where x3 is a dummy variable and I want to do the regression only
> using the observations where x3 is equal to 1. However I receive an
> error message saying that "if is not allowed". Could you suggest a way
> to do this?
>
> Thank you very much,
> Sarah
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