st: reg3 is not doing what I need it to do, suggestions?

[Anna G <anna_i_g@yahoo.com>]

Dear Statalist members,
thank you so much for your incredible help so far.
 
I have a question regarding reg3.
 
I am trying to estimate the following system of equations:
z=x-hat $variables
x=y-hat prices $variables
y=assets $variables
 
I am coding this as
reg3 (z x $variables)
    (x y prices $variables)
    (y assets $variables)
 
The results however do not seem to be giving me the coefficients on y-hat and x-hat but rather on y and x.
 
Any suggestions? I've read thoroughly the reference on the command, and the discussion on reg3 in the statalist.
 
For people interested, the following are my variables:
z - nutritional status z-score of children in the household
x - caloric availability at the household level
y - income, hh-level
 
The above are all simulataneously determined. 
 
variables -- hh and province-level controls.
 
Thank you in advance.
Best,
Anna
Stata 8.2 intercooled on windows xp
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/