A few weeks ago, I asked re: regression with clustered data, and was steered toward a mixed model. I am working with -xtmixed- now. There are hospital level (level 3) and unit level (level 2) effects on people (level 1), and both unit and hospital are easily accommodated with -xtmixed-.
The -xtmixed- command I am using is something like this:
.xtmixed t_rc no_pes t_cweq ||hosp_id: ||unit_id:, mle
In a two-level model, I would use -loneway- to get the intra-class correlation for level-2 effects (fully unconditional model).
I did that here,
.loneway t_rc unit_id
I also did that for level-3 as follows, but am not sure this is correct:
.loneway t_rc hosp_id
In Bryk & Raudenbush (1992), in the chapter on 3-level models, the "proportion of variance among" level-2 units (classrooms) is described as "variance among classrooms within schools." This language is confusing to me, as I am guessing that the proportion of level-2 variance in a fully unconditional model does not account for level-3, except in the denominator. Is that correct? Or should I be running the fully unconditional 3-level model to get these variance estimates?
Thanks in advance.
Cathy
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