--- 宋时歌 <[email protected]> wrote:
> I am estimating a set of random effect model using XTMIXED. My data
> has quite some missing values on important covariates. I use ICE to
> do multiple imputation and use MIM to automatically combine the
> results.
>
> The estimation seems fine, but when I try to get postestimation
> results, I have some problems. Here is what I did:
>
> mim: xtmixed height age boy ...||id:age, mle
> mim: estat ic
>
> I got error message "command estat not recognised by mim; try
> specifying category option". Then I tried:
>
> mim, cat(fit) estat ic
>
> I got "cat(fit) estat ic not allowed"
>
> If I have log likelihood, I can compute BIC and AIC myself, but the
> MIM seems to suppress that part of model output.
>
> My question is: what should I do to get log likelihood value from
> models on multiply imputed data set using MIM?
There is good reason why -mim- suppresses the log likelihood: it does
not exist after multiple imputation. Multiple Imputation gives you an
approximation of the model for each parameter separately; simultaneous
tests of multiple parameters, or model fit statistics don't behave very
well after multiple imputations. Some corrections do exist, and some
are implemented in -mim-, but this is very much still an area of active
research. What is possible in terms of post-estimation can be seen in
the section "Examples - Post Estimation" in the help-file of -mim-.
Hope this helps,
Maarten
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room Z434
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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