<>
So here is an implementation of Eva`s excellent advice as to the causes of
Mandy`s problem:
*************
clear*
set mem 400m
* enter the percentage of missings here
loc mis 0.01
u http://www.stata-press.com/data/imeus/traffic, clear
foreach var of varlist fatal beertax spircons unrate perincK {
replace `var'=. if runiform()<`mis'
}
qui xtreg fatal beertax spircons unrate perincK, fe
tempvar dummy
g `dummy'=e(sample)
qui ds, not(type string)
foreach var of varlist `r(varlist)'{
egen std`var'=std(`var') if `dummy'
}
xi: reg fatal beertax spircons unrate perincK i.state if `dummy', beta
xtreg stdfatal stdbeertax stdspircons stdunrate stdperincK if `dummy', fe
*************
HTH
Martin
_______________________
----- Original Message -----
From: "Mandy fu" <[email protected]>
To: <[email protected]>
Sent: Tuesday, March 03, 2009 9:40 PM
Subject: Re: st: AW: can I get standardized coefficients by standardize
variables first?
Dear Mr. Weiss,
Thanks for providing the example data. I really like the idea of
checking different percentage of missing to compare the results from
the two methods.
This is what's shown when changing the percentage of missing:
-------------------------------------------------------------------
when missing percentage is zero: coincide
when missing percentage is 0.01: differences are very small
when missing percentage is 0.01: differences are still small
when missing percentage is 0.3: differences are obviously larger
----------------------------------------------------------------
So, I'm thinking this shows well that the missing values explains the
differences of the two methods. They give the same results when
adjusting the missing values.
Thanks !
Mandy
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