st: Multiple membership model with xtmixed

[Steven Raemaekers <s.raemaekers@sig.eu>]

Hello,

I have a complex data structure I'm trying to model with xtmixed. 
There exists a multiple membership hierarchy in my data, which means that units at one level can belong to multiple units at the next level.
The command is as follows:

xtmixed dep iv2 iv3 || A: iv3 || B:, mle var cov(un)

One unit of B can be part of multiple units of A. How can I account for this in the xtmixed model, or maybe I do not need to do anything?
I saw the "_all: R." syntax, but if I'm not mistaking this is for cross classified hierarchies only, which is something else, or is it the same?
I cannot find anything about this in the help files. 

Regards,

Steven Raemaekers



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