<>
Well, this thread has produced three options for you to choose from, and you
have heard all the pros and cons. Just to summarize:
*************
sysuse auto, clear
/*first option */
qui gen ia2 = head*length
reg mpg head length ia2, beta
/*second option */
qui{
egen shead = std(headroom)
egen slength = std(length)
egen smpg = std(mpg)
replace ia2 = shead*slength
egen sia2 = std(ia2)
}
reg smpg shead slength sia2
/*third option */
reg mpg shead slength sia2
*************
HTH
Martin
-----Ursprüngliche Nachricht-----
Von: [email protected]
[mailto:[email protected]] Im Auftrag von
[email protected]
Gesendet: Sonntag, 21. Juni 2009 17:33
An: [email protected]
Betreff: Re: st: re: beta coefficients for interaction terms
I am sorry, but I am getting kind of confused here. I am not a pro in
running regressions with interaction terms, I am sorry that I have to
ask so many questions.
To get the beta coefficients I have to run the regression
.reg smpg shead slength sia2
If I run the regression
.reg mpg shead slength sia2
I get the coefficients, that are not standardized?
Am I right?
Best,
Lisa
Zitat von Kit Baum <[email protected]>:
> <>
> Martin said
>
> " so it is not telling you anything for which you need to estimate the
> regression to find out."
>
> So the point estimate is equal to ouput of other commands, bout how
> about
> the CI?
>
>
>
> The unconditional CI is larger:
>
> . means mpg
>
> Variable | Type Obs Mean [95% Conf.
> Interval]
> -------------+----------------------------------------------------------
> mpg | Arithmetic 74 21.2973 19.9569
> 22.63769
> | Geometric 74 20.58444 19.38034
> 21.86335
> | Harmonic 74 19.92318 18.81185
> 21.17405
> ------------------------------------------------------------------------
>
> because the standardized regressors that are added to the model are
> indeed correlated with mpg:
>
> _cons | 21.2973 .4121741 51.67 0.000 20.47524
> 22.11935
>
> but as you can see that doesn't make much difference in testing any
> meaningful hypothesis about the mean of mpg.
>
>
>
> Kit Baum | Boston College Economics & DIW Berlin |
> http://ideas.repec.org/e/pba1.html
> An Introduction to Stata Programming |
> http://www.stata-press.com/books/isp.html
> An Introduction to Modern Econometrics Using Stata |
> http://www.stata-press.com/books/imeus.html
>
>
>
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