Dear all,
I have been using Gretl recently to estimate proportion of staff, I have
three groups and the sum of the three proportion equals to 1. According to
Wooldridge (2002) this can of "share" systems can be estimated by SUR models
with Feasible GLS estimation (p. 167). Accordingly I can remove one
equation.
This is one of the models I estimate
"Skill-Mix Gap" <- system
equation pNHDfteHT2 const cvnbbeds avgnbbeds nbhospital Found TypeHT_1
TypeHT_2 TypeHT_4 TypeHT_5 gapNCo0305recod gapHCo0305recod gapMCo0305recod
equation pHDNfteHT2 const cvnbbeds avgnbbeds nbhospital Found TypeHT_1
TypeHT_2 TypeHT_4 TypeHT_5 gapNCo0305recod gapHCo0305recod gapMCo0305recod
endog pNHDfteHT2 pHDNfteHT2
instr const cvnbbeds avgnbbeds nbhospital Found TypeHT_1 TypeHT_2 TypeHT_4
TypeHT_5 gapNCo0305recod gapHCo0305recod gapMCo0305recod
end system
estimate "Skill-Mix Gap" method=sur --iterate
The estimation is computed, no problems
I put iterate but the estimation is done with just one iteration. In the
command GRETL reference book I read that with iterate the estimation is the
maximum likelihood one.
I am completely lost because I would like to know how does that work, I
would prefer to have FGLS as in Wooldridge (my reference book in
econometrics).
There is not so much information around (or at least I have not found it)
about how SUR are being estimated.
If someone could help me, that would be great, I am presenting tomorrow and
I am a bit nervous,
Cheers,
Jean-Baptiste