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RE: st: Mata : getting covariance matrix with optimize()
From
[email protected] (Gustavo Sanchez)
To
[email protected]
Subject
RE: st: Mata : getting covariance matrix with optimize()
Date
Thu, 10 Mar 2011 10:21:00 -0600
Maxime <[email protected]> provided additional details on his original
question about being able to get the covariance matrix when using the Mata
optimize function with method "gn" combined with a weight matrix.
We have not implemented variance estimation for this case, and Maxime
discovered that -optimize_result_V()- returns a matrix of zeroes -- obviously
not the correct variance matrix.
One could argue that -optimize_result_V()- should report an error for this
case, we will consider changing -optimize_reslt_V()- to do so.
In the mean time, Maxime could use â??gmm- (new in Stata 11) to perform the
estimation and obtain the corresponding covariance matrix. -gmm- is a
programmable estimation command, with a simple syntax for specifying the
moment conditions.
Maxime could write to me privately in case he needs some assistance with
syntax for â??gmm-.
--Gustavo
[email protected]
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