st: providing raw weights for multivariate meta-analysis

[Nick Darson <nick.darson@googlemail.com>]

Dear Statalisters,

I attempt to carry out a multivariate meta-analysis using "xtmixed". I
have three outcome measures (the first level).

When using a multilevel approach for the multivariate meta-analysis, I
read that it is important to provide raw-weights (non-normalized) of
the inverse sampling variances for the first level (containing the
outcome measures).

I know that HLM6 has a special function for this ("V-known") for two
and three level models.

Now, I wanted to know whether "pweights" is an equivalent solution for
xtmixed in Stata?

I must admit that I am a bit confused by the various descriptions of
the weight functions I found online (aweights, iweights, etc - though
this are not allowed for xtmixed) .

Moreover, surprisingly,  I read in Hox (2010,p. 230) that public
domain software for multilevel analysis does not support the required
options for a multivariate model so far (i.e. providing raw weights
and being able to constrain the lowest-level variance to 1 - however,
both should be feasible).

Thanks a lot for your support.
Nick Darson
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