Rabe-Hesketh, Skrondal and Gjessing (2007) discuss this problem, refer
to Guo and Wang (2002), and provide two example solutions in Stata 9
using the official -xtmixed- for a continuous response and the
user-written -gllamm- for a dichotomous response. For Stata 10, see
http://www.stata.com/stata10/mixedmodels.html.
References:
Rabe-Hesketh, S. Skrondal, A. and Gjessing, H. K. (2007). Biometrical
modeling of twin and family data using standard mixed model software.
Biometrics, in press. (accessed from http://www.gllamm.org/pub.html)
Guo, G. and Wang, J. (2002). The mixed or multilevel model
for behavior genetic analysis. Behavior Genetics 32, 37–49.
Anders Alexandersson
[email protected]
Jake Felson <[email protected]> wrote:
I'm wondering about whether Stata 9.0, or the upcoming
Stata 10.0 allows the user to fix elements of the
error variance matrix in the mixed model setting. This is required for
behavior genetic models described by Guang Guo (2002: behavior genetics).
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