TJ:
The program should call local macro's and temporary variable names. Both begin with a ` and end
with a '. Note that ` and ' are not the same. So your programe should be:
program hurdle_ll
version 8
args lnf beta1 beta2
tempvar pi lambda
quietly generate double `pi' = exp(`beta1')
quietly generate double `lambda' = exp(`beta2')
quietly replace `lnf' = cond($ML_y1==0,-`pi', ///
log(1-exp(-`pi')) + $ML_y1*`beta2' - ///
log(exp(`lambda')-1) - lngamma($ML_y1+1))
end
HTH,
Maarten
--- Brooks Taggert J <[email protected]> wrote:
> So I'm trying to estimate a hurdle model, actually before I do that I'm just trying to replicate
> the program in Stata Journal Vol 3 Issue 2 (p178) <snip> Any thoughts?
> here is the program:
>
> program hurdle_ll
> version 8
> args lnf beta1 beta2
> tempvar pi lambda
> quietly generate double 'pi' = exp('beta1')
> quietly generate double 'lambda' = exp('beta2')
> quietly replace 'lnf' = cond($ML_y1==0,-'pi', ///
> log(1-exp(-'pi')) + $ML_y1*'beta2' - ///
> log(exp('lambda')-1) - lngamma($ML_y1+1))
> end
>
> ml model lf hurdle_ll (y = x1 x2) (x1 x2)
> ml max, nolog
>
-----------------------------------------
between 1/2/2006 and 31/3/2006 I will be
visiting the UCLA, during this time the
best way to reach me is by email
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting adress:
Buitenveldertselaan 3 (Metropolitan), room Z214
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
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