Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

Re: st: 'Rolling' Slope Dummy


From   Richard Williams <Richard.A.Williams.5@nd.edu>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: 'Rolling' Slope Dummy
Date   Sat, 05 Mar 2005 20:48:12 -0500

At 12:32 AM 3/6/2005 +0000, Robert Gaskell wrote:
Thanks very much for that - your notes have been extremely helpful and
answered my question fully!  However, I have found that when
introducing these 'interaction effects between continuous variables',
if I include the slope term *or* the intercept term the coefficients
are significant, but when including both (as you suggest), the
coefficients are insignificant.  Does the intercept term need to be
included where the mid-point of the variable that is being added in is
zero, as in this case?

Best regards,
Robert Gaskell
I'm not quite sure what you are doing - by "intercept" do you mean the dummy variable for group membership? Or, do you literally mean that you have specified -noconstant- when running your models? Anyway, whatever you mean, my guess is you want it (constant and/or dummy variable) in there.

You might try posting a simple example of the generate and regress commands that you are using so we can see what is going on (it might be that there is an error and my directions were not so clear after all!). Or, email to me separately and I'll take a look.

-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
FAX: (574)288-4373
HOME: (574)289-5227
EMAIL: Richard.A.Williams.5@ND.Edu
WWW (personal): http://www.nd.edu/~rwilliam
WWW (department): http://www.nd.edu/~soc

*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* 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   |   What's new   |   Site index