-constraint- only excepts equality constraints.
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Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting adress:
Buitenveldertselaan 3 (Metropolitan), room Z214
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
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-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu]On Behalf Of Stephan Brunow
Sent: donderdag 6 april 2006 14:37
To: statalist@hsphsun2.harvard.edu
Subject: st: inequality constraints for regression models
we want to estimate a regression model (Zellners SUR model) with some
restrictions on parameters and equal explanatory variables. Especially we
want to say that the parameters have to be between 0 and 1.
At the moment we wrote
Constraint define 1 [eq1]variable1>=0 & [eq1]variable1<=1
Sureg (yvar1-yvar3 = variable1), cons(1)
The error message we get is
'not possible with test - r(131)'
What did we wrong? Finally, it turns out that the question is: How to write
the constraint?!
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