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Stata FAQ
How do I analyze survey data with a systematic sample design?

The examples below use Stata 9.  If you are using Stata versions 7 or 8, please see this page.

NOTE:  If you want to see the design effect or the misspecification effect, use estat effects after the command.

This example is taken from Lehtonen and Pahkinen's Practical Methods for Design and Analysis of Complex Surveys.

page 46 Table 2.6  Estimates from a systematic sample drawn from the Province'91 population using implicit stratification.

NOTE:  The standard error of the total is different from that shown in the text (the text shows 11802).  However, we get the 13627 in each of the statistical packages in which we have tried to recreate this example.

input id str clu wt ue91 lab91
1 1 1 4 4123 33786
2 1 5 4 721 4930
3 2 9 4 194 2069
4 2 13 4 129 927
5 2 17 4 239 2144
6 2 21 4 61 573
7 2 25 4 262 1737
8 2 29 4 166 1615
end

gen fpc = 32

svyset clu [pweight=wt], strata(str)

      pweight: wt
          VCE: linearized
     Strata 1: str
         SU 1: clu
        FPC 1: <zero>

svy: total ue91
(running total on estimation sample)

Survey: Total estimation

Number of strata =       2          Number of obs    =       8
Number of PSUs   =       8          Population size  =      32
                                    Design df        =       6

--------------------------------------------------------------
             |             Linearized
             |      Total   Std. Err.     [95% Conf. Interval]
-------------+------------------------------------------------
        ue91 |      23580   13627.19     -9764.529    56924.53
--------------------------------------------------------------

svy: ratio ue91 lab91
(running ratio on estimation sample)

Survey: Ratio estimation

Number of strata =       2          Number of obs    =       8
Number of PSUs   =       8          Population size  =      32
                                    Design df        =       6

     _ratio_1: ue91/lab91

--------------------------------------------------------------
             |             Linearized
             |      Ratio   Std. Err.     [95% Conf. Interval]
-------------+------------------------------------------------
    _ratio_1 |   .1233754    .003848      .1139596    .1327912
--------------------------------------------------------------

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