Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Standard errors in first stage ivregress vs. reg

From   Christopher Baum <>
To   "" <>
Subject   Re: st: Standard errors in first stage ivregress vs. reg
Date   Tue, 6 Dec 2011 07:09:51 -0500

On Dec 6, 2011, at 2:33 AM, Ingo wrote:

> I want to reproduce the first stage of ivregress by using reg to get
> access to the coefficient vector and covariance matrix. Unfortunately,
> the standard errors differ between
> ivregress 2tsls y x1 (x2 = z), robust firststage
> and
> reg x2 x1 z, robust
> The point estimates are the same, the standard errors differ
> (marginally). This problem only occurs if I estimate the model with
> robust standard errors.
> To make it clear, I only refer to differences in the first stage,
> which I do not understand. Is there any other way to obtain the
> estimates to use them in estout?

Yes. The -savefirst- option in Baum-Schaffer-Stillman's -ivreg2-, on SSC, does this for a living.


Kit Baum   |   Boston College Economics & DIW Berlin   |
                             An Introduction to Stata Programming  |
  An Introduction to Modern Econometrics Using Stata  |

*   For searches and help try:

© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index