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st: constraints insufficient for unique estimate


From   "Zeynal Karaca" <zeynal@tamu.edu>
To   statalist@hsphsun2.harvard.edu
Subject   st: constraints insufficient for unique estimate
Date   Wed, 10 Aug 2005 18:21:24 -0500

Hi, 

I need some help on the following case:

The equation that I am running is a simple linear reggression model.
Basically,

constraint define 1 x1=x2

cnsreg Y x1 x2 x3 x4 x5 c1 c2 c3 c4 c5 c6 c7 c8 c9 c10 c11 c12 c13 
c14 c15 c16 c17 c18 c19 c20 c21 c22 c23 c24 c25 c26 c27 c28 c29 c30 
c31 c32 c33 c34 c35 c36 c37 c38 c39 c40 d1 d2 d3 d4 d5 d6 d7 d8 d9 
d10 d11 d12 d13 d14 d15 d16 d17 d18 d19 d20 d21 d22 d23 d24 d25 d26 
d27 d28 d29 d30 d31 d32 d33 d34 d35 d36 d37 d38 d39 d40 ,constraint
(1) 

Here the dependent variable is expenditures, the right hand variables
all are dummy variable for ceratin groups, for example, c1..c40 for 
therapeutic conditions.

When I run the regression it gives me the following error:

constraints insufficient for unique estimate
redundant or inconsistent constraints

But, when I decrease the number of dummy variables for each category
to 5, the regression is going through. But I need to use all the
dummy
variables becasue all of them seperated and unique and it is crucial 
for my dissertation. So, please help me out if I am missing something 
in the code or should I use a different definition for the
constraint?

Zeynal Karaca
Texas A&M University
Department of Economics
3005 Academic Building West
College Station, TX   77843-4228
Phone:1-979-8458782

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