Hi,
you may want to give a look at the feedback I got last week from Mark
Schaffer and Marcela Perticara to my post on -xtreg- vs -regress,
cluster- (Dec 5). I think their replies apply to your post as well.
Good luck,
Enrica
On Tue, 10 Dec 2002, Lee Chuntao wrote:
> Hi Listers,
>
> I have run an xtreg with 3 explanatary variables.
>
> the result shows that, there are within and between variations, whereas the
> sigma_u is zero.
>
> can you tell me why?
> thanks
>
>
>
> xtreg invest l_tobinq cash nta
>
> Random-effects GLS regression Number of obs =
> 1680
> Group variable (i) : i Number of groups =
> 280
>
> R-sq: within = 0.0862 Obs per group: min =
> 6
> between = 0.5242 avg =
> 6.0
> overall = 0.1601 max =
> 6
>
> Random effects u_i ~ Gaussian Wald chi2(3) =
> 319.48
> corr(u_i, X) = 0 (assumed) Prob > chi2 =
> 0.0000
>
> ----------------------------------------------------------------------------
> --
> invest | Coef. Std. Err. z P>|z| [95% Conf.
> Interval]
> -------------+--------------------------------------------------------------
> --
> l_tobinq | .1258068 .0586902 2.14 0.032 .0107761
> .2408374
> cash | .1442353 .008403 17.16 0.000 .1277656
> .160705
> nta | -.1554083 .0710843 -2.19
> 0.029 -.294731 -.0160855
> _cons | 3.458639 1.513534 2.29 0.022 .4921665
> 6.425112
> -------------+--------------------------------------------------------------
> --
> sigma_u | 0
> sigma_e | 2.6171947
> rho | 0 (fraction of variance due to u_i)
> ----------------------------------------------------------------------------
> --
>
>
> *
> * 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/
>
*
* 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/
