Re: st: command stata

[Richard Williams <richardwilliams.ndu@gmail.com>]

Adding to Maarten's suggestions, the new -sem- (Structural Equation 
Modeling) module in Stata 12 makes it very easy to estimate MIMIC 
modules. See example 10 in the sem manual. I wish -sem- had been 
around 30 years ago back when I was struggling with the classic LISREL program.

To offer further insights on the original question, we really do need 
to know how the original variables are coded and what Donsaane means 
when she says she wants to "group them into one variable."

At 02:46 AM 8/26/2011, Maarten Buis wrote:
> 2011/8/26 Donsaane Dontsi Saatena :
> > I am looking for stata's command in order to group many variables into one.
> > Let's say we have: roads, water , electricity, and we want to group them
> > into one variable: infrastructures.
>
> --- Rich Williams proposed
> > Does -egen- with the group function do what you want?
>
> What Rich proposes is in essence to create one categorical variable
> that has a unique value for each combination of values on each of the
> three variables. I read this question differently. I interpret it that
> you want to make a metric variable that indicates how good the
> infrastructure is.
>
> Here there is a subtle but important distinction between whether you
> believe that the observed variables influence the latent variable or
> the other way around. Consider an intelligence test; here we believe
> that there is some latent intelligence that makes people answer
> questions right or wrong, so the observed variables (whether or not
> questions were answered correctly) are caused by the latent variable.
> In your case it makes more sense to think of roads, water and
> electricity as feeding into a pool of resources that we labelled
> infrastructure, so now it is the observed variables that cause the
> latent variable. In the former situation you would use factor analysis
> and their kin, in the latter (your) situation you would use sheaf
> coefficients, models with parametrically weighted covariates or MIMIC
> models. These have been implemented in Stata in the -sheafcoef- and
> -propcnsreg- packages, which can be obtained from SSC by typing in
> Stata -ssc install sheafcoef- and ssc install propcnsreg-. You can
> find out more about them here:
> <http://www.maartenbuis.nl/wp/prop.html>
>
> Hope this helps,
> Maarten
>
> --------------------------
> Maarten L. Buis
> Institut fuer Soziologie
> Universitaet Tuebingen
> Wilhelmstrasse 36
> 72074 Tuebingen
> Germany
>
>
> http://www.maartenbuis.nl
> --------------------------
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/

-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
HOME:   (574)289-5227
EMAIL:  Richard.A.Williams.5@ND.Edu
WWW:    http://www.nd.edu/~rwilliam

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/