Deepankar Basu wrote:
> I am trying to estimate a fertility model with birth history data using maximum likelihood. The data comes from a survey (DHS) and I am using Stata 8.1.
>
> When I run *ml check*, I get the message that all tests have been passed. Then, once the optimization starts, the program spits out the error message that "numerical derivatives could not be calculated" and stops. Any suggestions on how to go about finding the error, correcting it and making the program work?
I can't advise on your program, but you should at least update to
Stata 8.2 and see if that changes anything.
--
Clive Nicholas
[Please DO NOT mail me personally here, but at
<[email protected]>. Thanks!]
"Courage is going from failure to failure without losing enthusiasm."
-- Winston Churchill
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