st: svy commands, missing data, and stratum with only one PSU

["Suzanne Bouffard" <bouffasu@gse.harvard.edu>]

I am using a large national dataset and am trying to use the svy commands. In this dataset, there 
are several missing codes, which range from -1 to -9. When I run svyprop on the raw data, it works 
just fine. However, when I recode all of the missing data to ".", I get the error message "stratum 
with only one PSU detected."  Evidently, when I recode the missing data, Stata thinks that there 
are no people in certain PSU's.

How do I deal with this problem? It is happening with all of the variables I have tried.

Thanks for any help you can provide.
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