Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


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

Re: Re: st: Normalize Variables by s.d. (programmatically)


From   Christopher Baum <kit.baum@bc.edu>
To   "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>
Subject   Re: Re: st: Normalize Variables by s.d. (programmatically)
Date   Fri, 23 Dec 2011 09:44:02 -0500

<>
On Dec 23, 2011, at 2:33 AM, Daniel wrote:

> If you already have created your dummies, you migth want to pass them
> in an option. This way you do not need to identify the dummies in
> <varlist>.

Good point. We can go one better (now that I have been enlightened on the difference between fvunab and fvexpand) with:

-----------------------------------------
prog drop _all
prog stdize2
syntax varlist(ts) [if] [in] [, dummies(varlist fv ts) *]
tsunab vl: `varlist'
marksample touse
tempvar rs
qui g `rs' = 0 if `touse'
foreach w of local vl {
	qui replace `rs' = `rs' + `w' if `touse'
}
preserve
foreach w of local vl {
	qui summ `w' if `touse' & !mi(`rs')
	tempvar ww
	qui g `ww' = `w' / r(sd) if `touse' & !mi(`rs')
	loc neww: subinstr loc w "." "_"
	rename `ww' _`neww'
	loc vl2 "`vl2' _`neww'"
}
fvexpand `dummies'
xtreg `vl2' `r(varlist)', `options'
restore
end
--------------------------------------------

which will now, using the grunfeld dataset, allow the use of factor variables to represent a set of time fixed effects, a common
issue in a panel:

stdize2 invest D.mvalue L(1/2).kstock if company<7, fe dummies(i.year)

Best wishes of the season
Kit

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


*
*   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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index