--- "F. Gao" <[email protected]> wrote:
> I have a question regarding statistical models. I have a panel data
> with obs on people's background information (age, wealth from other
> sources, etc), and wage if the person decides to work. A person may
> choose to work, if so, there is an observable wage; if not, wage is
> 0.
>
> I am confused about what models to use. It looks like a standard
> tobit model, with wage censored at 0. Below is an alternative way to
> model.
>
> A: Probit model of the decision to work or not.
> B: For wage>0 observations, use OLS regression.
>
> I have seen both in practice. But while using two models, the authors
> mention that they are estimating both model A and model B at the same
> time. What does it mean "at the same time"?
They are probably doing more than just estimate model A and B, see:
-help heckman-
> Bottom line:
> If both tobit and the joint estimation of models A and B are
> appropriate, which is better?
That's a tough question. A short readable text is: Breen,
Richard (1996), "Regression Models: Censored, Sample-selected, or
Truncated Data". Thousand Oaks: Sage.
Hope this helps,
Maarten
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
___________________________________________________________
Yahoo! Answers - Got a question? Someone out there knows the answer. Try it
now.
http://uk.answers.yahoo.com/
*
* 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/
