Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


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

Re: st: Dependent ordered variable


From   Tirthankar Chakravarty <tirthankar.chakravarty@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Dependent ordered variable
Date   Mon, 28 May 2012 01:24:22 -0700

You don't say which version of Stata you are using. Most of what -xi-
and -xi3- (ATS UCLA) could do have been superseded in Stata 12.

You should explicitly declare your credit rating variable as a factor
variable, as in your (2) or (3) - the effects coding doesn't really
matter and is a matter of interpretability - which is the main
difference between your (2) and (3). In Stata 12, the first regression
below gives you the indicator coding from your (2), the following line
gives you the backward adjacent coding from your (3):

*********************************
sysuse auto, clear
reg mpg i.rep78
contrast a.rep78
xi: reg mpg i.rep78  // (2)
xi3: reg mpg b.rep78  // (3)
*********************************

In general, the advice is that if you are using Stata 12, then look
into -fvvarlist-, -contrast-, -pwcompare-, and -margins- for very
general ways of dealing with factor/categorical regressors.

T



On Mon, May 28, 2012 at 12:52 AM, Tobias Bertschinger
<tobias.bertschinger@uzh.ch> wrote:
> Hi
> I'm currently analyzing data which have an approximately normal distributed dependent variable Y (dependent_var) and I also have a couple of dependent variables.
> I want to test the influence of credit ratings (ordered, e.g. AAA, AA+, AA, AA-...) as the main independent variable and a couple of control variables.
>
> What kind of test should i use?
> Are there other tests than:
> (1) include the credit rating as a dummy variable
> (2) use xi: regress dependent_var i.credit_rating control_vars
> (3) use xi3: regress dependent_var b.credit_rating control_vars
> ?
>
> Thanks for your help!
> *
> *   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/



-- 
Tirthankar Chakravarty
tchakravarty@ucsd.edu
tirthankar.chakravarty@gmail.com

*
*   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 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index