Re: st: Comparing coefficients between two samples

 From John Antonakis To statalist@hsphsun2.harvard.edu Subject Re: st: Comparing coefficients between two samples Date Mon, 30 Mar 2009 20:42:28 +0200

I don't think it would be a problem if your equation is overidentified. If you are worried about having an endogenous dummy, that should not be a problem either. Check out the paper by Angrist:
```
http://ideas.repec.org/p/nbr/nberte/0248.html

Perhaps others have ideas.

Best,
J.

____________________________________________________

Prof. John Antonakis
```
Associate Dean Faculty of Business and Economics
```University of Lausanne
Internef #618
CH-1015 Lausanne-Dorigny
Switzerland

Tel ++41 (0)21 692-3438
Fax ++41 (0)21 692-3305

e-mail: john.antonakis@unil.ch

____________________________________________________

On 30.03.2009 20:26, Erasmo Giambona wrote:
```
```Dear John,

Thanks very much for your suggestion. I wonder whether this would
still be fine when the variable of interest is the endogenous
variable.

Regards,

Erasmo

On Mon, Mar 30, 2009 at 6:32 PM, JOHN ANTONAKIS <john.antonakis@unil.ch> wrote:
```
```Hi Erasmo:

One solution may be to create an indicator variable (for the groups) that
you interact with your variables of interest?  A significant interaction
indicates that the coefficients are not the same across the two groups.

HTH,
John.

____________________________________________________

Prof. John Antonakis
Associate Dean Faculty of Business and Economics
University of Lausanne
Internef #618
CH-1015 Lausanne-Dorigny
Switzerland

Tel ++41 (0)21 692-3438
Fax ++41 (0)21 692-3305

____________________________________________________

On 30.03.2009 17:06, Erasmo Giambona wrote:
```
```Dear Statalist,

I am fitting the same exact model to two different samples using
xtivreg2. I would like to test whether the coefficients on the
endogenous variables are statistically different from each other
across the two groups.

I understand that this test can be performed with suest after regress,
but suest does not work after xtivreg2.

I would appreciate any suggestions on how I could perform this test in
this case.

Regards,

Erasmo
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