Dear statalisters,
I am a new user of IV methods and I would be grateful if you would help me.
I want to test whether a particular variable, bmi, is exegenous, so i run
ivreg2 Y bmi (=VARiv), orthog(bmi) is that correct?
I get the following statistics
------------------------------
------------------------------------------------
mah4 | Coef. Std. Err. z P>|z| [95% Conf.
Interval]
-------------+----------------------------------------------------------------
bmi | -.176151 .0587376 -3.00 0.003 -.2912745
-.0610274
_cons | 50.08047 1.457251 34.37 0.000 47.22431
52.93663
------------------------------------------------------------------------------
Sargan statistic (Lagrange multiplier test of excluded instruments):
23.173
Chi-sq(1) P-val =
0.0000
-orthog- option:
Sargan statistic (eqn. excluding suspect orthogonality conditions):
0.000
Chi-sq(0) P-val
= .
C statistic (exogeneity/orthogonality of suspect instruments):
23.173
Chi-sq(1) P-val
= 0.0000
Instruments tested: bmi
------------------------------------------------------------------------------
Included instruments: bmi
Excluded instruments: fto
------------------------------------------------------------------------------
Questions:
1) the C stat shows that bmi is endogenous and IV method is appropriate?
2)the Sargan stat confirms that VARiv is endogenous? and how to
interpret the orthog-option in this example ?
Thanks in advance
Mohamed
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