Statalist The Stata Listserver


[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

RE: st: IV with oprobit / mprobit?


From   "Brian P. Poi" <bpoi@stata.com>
To   statalist@hsphsun2.harvard.edu
Subject   RE: st: IV with oprobit / mprobit?
Date   Wed, 15 Mar 2006 11:15:50 -0600 (CST)

On Wed, 15 Mar 2006, Tobias Hofmann wrote:

Dear Brian, dear all,

Thanks for your quick response!

Not knowing what exactly Bart was looking for, I envisioned - as you
correctly assumed - a model in which the endogenous regressor is an ordered
categorical variable and the dependent variable is continuous (i.e. the
first stage is fitted via -oprobit- and the second stage via -regress-).

Now, my follow-up question referred to the corrected standard errors from
the second stage regression. By elaborating on the code provided (see
below), how could the corrected standard errors be "made" robust (as Stata
would do if you added the -, robust- or -, cluster(var)- options to an
existing/implemented estimation command) in a simple way.

Your guess that the treatment effects literature may have something to say
about that is most probably correct. Being a novice to this literature, I'm
wondering whether you could provide me with a couple of more precise
references? Thanks!

Best regards,
Tobias

Regarding robust covariance matrices for two-step estimators, there was an article by James Hardin in the Stata Journal (2002, v. 2, #3). The tricky part is in getting all of the required derivatives.

There is an article by Angrist and Imbens in the Journal of the American Statistical Association (1995, v. 90, #430) that discusses treatment effect estimation with variable treatment intensities.

HTH

-- Brian Poi
-- bpoi@stata.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/




© Copyright 1996–2020 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index