I'm used to HLM 7 software and now I'd like to switch to Stata, for multilevel modelling (xtmixed).
To give an example imagine I have students(level1) nested within schools (level2).
In HLM I can easily add a second level variable (for instance schools beauty) choosing the equation of a coefficient (or intercept) which is at level 2.
Imagine I want to include the effect of school beauty in B0 (intercept).
How can I do that in Stata?
Best Answer
I found the solution here:
http://www.iub.edu/~statmath/stat/all/hlm/hlm.pdf
The answer is:
whereas HLM requires two separate data les (one corresponding to each level), SPSS, Stata, SAS, and R rely on only a single file. The level-2 observations are common to each case within the same macro-unit, so that if there are 50 students in one school the corresponding school-level score appears 50 times. Each program also requires an id variable identifying the group membership of each individual.
So, adding a second level variable to the model, like the school sector (Sector), can be easily done via the xtmixed command. For instance:
xtmixed MatGrade Intelligence Sector || SchoolId: Where "MatGrade" is the outcome variable, "Intelligence" is a level 1 variable reflecting the intelligence of the scholars. Scholars are nested within schools.