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From | Donald Spady <dspady@ualberta.ca> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Including components of a summative score in regression |
Date | Tue, 31 Jul 2012 09:40:12 -0600 |
Maarten Thanks for the reference. I'll try and get it at my University library. Don On 2012-07-31, at 1:35 AM, Maarten Buis <maartenlbuis@gmail.com> wrote: > 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/ > Donald Spady -- dspady@ualberta.ca * * 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/