Re: st: svyset for a multistage sampling design

["Michael I. Lichter" <MLichter@Buffalo.EDU>]

Tomeka,

1. If you don't supply a finite population correction option for the 
first stage [svyset psu, fpc()], svyset will ignore your second stage.
2. What are your school strata and how many of the strata have only only 
psu in them -- and why? It doesn't look to me like school is a 
stratifying variable -- it's your second stage sampling unit which will 
be ignored without the FPC.

-ml

Tomeka Davis wrote:
> 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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--
Michael I. Lichter, Ph.D. <mlichter@buffalo.edu>
Research Assistant Professor & NRSA Fellow
UB Department of Family Medicine / Primary Care Research Institute
UB Clinical Center, 462 Grider Street, Buffalo, NY 14215
Office: CC 126 / Phone: 716-898-4751 / FAX: 716-898-3536

*
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