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: Including components of a summative score in regression
From
Maarten Buis <[email protected]>
To
[email protected]
Subject
Re: st: Including components of a summative score in regression
Date
Tue, 31 Jul 2012 09:35:59 +0200
At 02:46 PM 7/30/2012, Donald Spady wrote:
>> I am doing some logistic regression analysis, some of the variables of
>> which are made up of the values of other variables; e.g. N = A + B + C/D.
>> Is it reasonable, or appropriate, to include A, B, C, or D in the
>> equation if N is already in it.
On Mon, Jul 30, 2012 at 11:12 PM, Richard Williams wrote:
> I believe the improvements in fit stem from
>
> * N constrains the coefficients of A and B and C/D to be equal; adding A and
> B relaxes two of those constraints.
Also see:
M.L. Buis (2012) "Stata tip 108: On adding and constraining", The
Stata Journal, 12(2), pp. 342-344.
Hope this helps,
Maarten
--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://www.maartenbuis.nl
--------------------------
*
* 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/