 |
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]
Re: st: problem with heckman procedure
On Tue, 25 Sep 2007, Zeenat Soobedar <[email protected]> wrote:
I am doing the heckman procedure using a loop because I need to do it
for several years But when STATA executes the command which is as
follows:
xi: heckman wf i.agegroup i.qual, twostep select(i.agegroup i.qual
i.agegroup*i.qual ym) mills(mills`y')
/* `y' stands for 1980 1990 2000 */
the program stops and I get the following error: matrix has missing
values
r(504);
So I drop the mills ratio generated and then rerun the same command and
then it works. But the thing is that I have to run this one line command
on its own.
Without seeing the dataset, it's hard to tell what is causing this error
message. Zeenat, if you send your dataset to me privately
([email protected]), I'd be happy to look into the problem for you.
-- Brian Poi
-- [email protected]
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/