st: Reliability of Aggregated Data

[한세희 <shkingdom@gmail.com>]

Hello,

I have a question regarding the reliability of aggregated data.
I was conducting a multi-level analysis (the individual is nested
within the district).
There are 5-items which are about mental health as an independent variable and
I want to use this as an aggregated variable(Originally it was measured at
the individual level, so I want to aggregate this variable into a district
level variable).
I heard that we cannot use Cronbach's alpha reliability coefficients as an
aggregated variable's reliability.
Is there any command that I can check an aggregated variable (which includes
more than 2-items)'s reliability in Stata?
Could you also let me know the equation as well?

Thanks!
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