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Re: st: Unknown function () error.
You could look up Cameron and Trivedi on counts or microeconometrics, Greene
(I think), the Stata manual entry for nbreg, etc. for the density function
and/or likelihood function for a negative binomial. Sorry I can't be more
specific because I don't have these books handy.
hth
Partha
Vimalanand S. Prabhu wrote:
Dear Partha,
Can you please make any suggestions as to how I can proceed?
Thanks,
Prabhu
Partha Deb wrote:
Watch the # - I think you want * .
Also, this isn't the likelihood function for a NB unless you do
something more with uu. As specified, since uu is a constant, it's a
Poisson with an additional constant (and hence not identified).
Partha
Vimalanand S. Prabhu wrote:
Hi
I am new to ml command. I am getting an error: Unknown function
(), when I run the following code for negative binomial count model.
Is there any obvious error in the code which I seem to miss out.
The L function is -exp(lambda.ui).(lambda.ui)^yi/(yi)!
program define nbreg2
args lnf theta uu
quietly replace `lnf' = -exp(`theta')#`uu' +
$ML_y1#(`theta'+ln(`uu')) - lnfact($ML_y1)
end
ml model lf nbreg2 (jdemh=price eff) ()
ml check
ml maximize
Thanks,
Prabhu
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--
Partha Deb
Department of Economics
Hunter College
ph: (212) 772-5435
fax: (212) 772-5398
http://urban.hunter.cuny.edu/~deb/
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