st: svyset command

[Rebecca Pietrelli <rebecca.pietrelli@gmail.com>]

Hi,

I am using the Stata command svyset in order to declare the survey
design for my dataset.
(Uanda Migration Housolds Survey 2010).

The sample design is two-stage stratified: in the first stage
enumeration areas -ea (psus) were selected, separately for rural and
urban areas, and in the second stage households were selected in each
ea, using a systematic procedure (4 hhs with international migrants, 3
with internal migrants and 3 without migrants).

I used the following command:
svyset psu_var [pw=hhweights_var], strata(strata_var)

and then (using svydes) I noticed that units = 191 instead of 200 (as
in the survey report) in one file of the dataset and units = 209 in
another file of the datset.

Are these differences plausible or not?
Or do they mean that I wrong the svyset command?
I am not sure if the first stage is with or without replacement (It is
not mentioned in the report).

Thank you very much for any help.
Rebecca
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