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]
st: Demeaning of variables in multiregression models interpretation of constant and interaction terms (
From
"Catharina Klepsch" <[email protected]>
To
<[email protected]>
Subject
st: Demeaning of variables in multiregression models interpretation of constant and interaction terms (
Date
Thu, 11 Nov 2010 13:24:31 +0100
Dear Stata users
I have a question concerning the following regression:
y = a+ b1x + b2D + b3C + b4(xD) + b5(CD)
D is a time dummy taking the value of one from a certain period of time
onwards
C = Countrydummy
X and C are each interacted with the Timedummy.
If I demean all x variables, the coefficients on a, b3 and b4 are very
logical. If I do the same regression without demeaning the variables, a, b3
and b4 have partly confusing signs.
Can anyone tell me why this is the case? I am not quite sure which one I
shall take.
For any help I am very grateful.
Best regards
C.K.
*
* 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/