# st: RE: program define quaids_delta

 From "Nelson, Carl" <[email protected]> To "[email protected]" <[email protected]> Subject st: RE: program define quaids_delta Date Wed, 3 Jun 2009 08:04:25 -0500

```Nigussie,

You are apparently looking at the old maximum likelihood code for nonlinear quaids. You
should look at the more recent nlsur code instead. It is much more efficient, easier to
code,  and more robust. A 22 commodity demand system sounds excessive, and almost
certain to be beset by estimation problems. You should probably aggregate down to
a more manageable set.

Carl Nelson
________________________________________
From: [email protected] [[email protected]] On Behalf Of nigussie Tefera [[email protected]]
Sent: Wednesday, June 03, 2009 6:19 AM
To: [email protected]
Subject: st: program define quaids_delta

Hello dear all

In specify non linear AIDS specification of gamma parameters are important. The specification of gamma for four equations which is given by help desk is given below.

/* gamma */
matrix `g' = ( 1,  0,  0,  0,  0,  0\ /*
*/  0,  1,  0,  0,  0,  0\ /*
*/  0,  0,  1,  0,  0,  0\ /*
*/ -1, -1, -1,  0,  0,  0\ /*
*/  0,  0,  0,  1,  0,  0\ /*
*/  0,  0,  0,  0,  1,  0\ /*
*/  0, -1,  0, -1, -1,  0\ /*
*/  0,  0,  0,  0,  0,  1\ /*
*/  0,  0, -1,  0, -1, -1\ /*
*/  1,  2,  2,  1,  2,  1 )
matrix `d'[(2*\$NEQN+1), (2*`nm1'+1)] = `g'

If I have 21 equations, how can I specify the gamma matrix? Any help is very much appericiated.

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```