I am trying to use the set of svy commands to analyze data collected using a multi-stage design. The first stage of sampling involved counties that were selected proportional to their size (N~100). Next, schools were sampled (N~400), and then students were randomly sampled within schools.
In this context, the county is the psu and the school is the strata. I am not sure how strata with one sampling unit were treated. Because I must have this option in STATA, I choose the certainty option since it contributes nothing to the standard error. Without the option, the program does not calculate standard errors.
My syntax looks like : svyset county [pweight=studentweight], strata (school) ||_n, singleunit (certainty)
The problem is that I am not clear if STATA is using all of the stages. After I enter the command, I get a message that says:
"Note: stage 1 is sampled with replacement; all further stages will be ignored".
I would appreciate any comments.
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