Dear gretl users,

I have a questions regrding coefficient wald tests.

I have estimated a SUR system (20 equations) and now I would like to conduct 
Wald tests for individual coefficients across different equations.

I know that I can use the restrict command e.g.

restrict "System"
b[1,2]-b[3,2]=0
end restrict

estimate "System" method=sur

which yields an F-test at the end.

However, I want to conduct the tests for several equations (14 out of 20) each 
with 8 coefficients, which would require a lot of individual restricitons.

Therefore, I asked myself, whether I could obtain the same results using

(b[1,2]-b[3,2])/S(diff),

where S(diff) =sqrt(S(b[1,2])^2+S(b[1,2])^2)

Unfortunately, the results between the two tests differ (even if I square the 
t-statistic).

Finally, I am looking for a way, to calculate the wald tests, without manually 
respecifying the every single restriction.

Thanks in advance.

Jan

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