Date: Wed, 4 Dec 2002 19:25:52 -0500
Reply-To: Rob Penfold <firstname.lastname@example.org>
Sender: "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From: Rob Penfold <email@example.com>
Subject: conditional logistic fails - nested solution in SPSS?
Content-Type: text/plain; charset="iso-8859-1"
I've run a conditional logistic regression and completed some tests of the
IIA assumption (deleting alternatives and looking at the consistency of the
parameters). In 2/119 cases the coefficients are inconsistent when the
alternative is deleted (i.e. I estimated the model 119 times since each
individual chooses from 120 alternatives). I don't know how to get the
covariance matrix from SPSS in order to do the Hausman test. I can't afford
STATA ($500 US for a grad student!!!!).
Is there a way to trick SPSS into doing a nested logistic regression? If
not, can I estimate separate conditional logit models - one for each of the
branches (groups 1, 2, 3) as an equivalent procedure? My tree is below.
Spatial Monopoly (zero competitors within 400m)
/ | \
(# competitors within 400m) 1 2 3
/|\ /|\ \
L1...L22 L3, L8, L21
L1 (locations where this happens - i.e. choices)
Thanks a million,
Department of Geography
University of Toronto
Scientia Est Potentia