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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 Levy and Lemeshow's Sampling of Populations.
page 53 simple random sampling
use http://www.ats.ucla.edu/stat/books/sop/momsag.dta, clear
svyset [pweight=weight1], fpc(birth)
pweight: weight1
VCE: linearized
Strata 1: <one>
SU 1: <observations>
FPC 1: birth
svy: mean momsag
(running mean on estimation sample)
Survey: Mean estimation
Number of strata = 1 Number of obs = 25
Number of PSUs = 25 Population size = 773
Design df = 24
--------------------------------------------------------------
| Linearized
| Mean Std. Err. [95% Conf. Interval]
-------------+------------------------------------------------
momsag | .92 .0544746 .8075699 1.03243
--------------------------------------------------------------
svy: total momsag
(running total on estimation sample)
Survey: Total estimation
Number of strata = 1 Number of obs = 25
Number of PSUs = 25 Population size = 773
Design df = 24
--------------------------------------------------------------
| Linearized
| Total Std. Err. [95% Conf. Interval]
-------------+------------------------------------------------
This example is taken from Lehtonen and Pahkinen's Practical Methods for Design and Analysis of Complex Surveys.page 29 Table 2.4 Estimates from a simple random sample drawn without replacement (n = 8); the Province'91 population.
input id cluster ue91 lab91 1 1 4123 33786 2 4 760 5919 3 5 721 4930 4 15 142 675 5 18 187 1448 6 26 331 2543 7 30 127 1084 8 31 219 1330 end
gen fpc = 32 gen wt = 4 gen strata = 1
svyset [pweight=wt], fpc(fpc)
pweight: wt
VCE: linearized
Strata 1: <one>
SU 1: <observations>
FPC 1: fpc
svy: total ue91
(running total on estimation sample)
Survey: Total estimation
Number of strata = 1 Number of obs = 8
Number of PSUs = 8 Population size = 32
Design df = 7
--------------------------------------------------------------
| Linearized
| Total Std. Err. [95% Conf. Interval]
-------------+------------------------------------------------
ue91 | 26440 13282.26 -4967.551 57847.55
--------------------------------------------------------------
estat effects
----------------------------------------------------------
| Linearized
| Total Std. Err. Deff Deft
-------------+--------------------------------------------
ue91 | 26440 13282.26 1 .866025
----------------------------------------------------------
Note: Weights must represent population totals for deff to be correct when using an FPC; however, deft is
invariant to the scale of weights.
svy: ratio ue91 lab91
(running ratio on estimation sample)
Survey: Ratio estimation
Number of strata = 1 Number of obs = 8
Number of PSUs = 8 Population size = 32
Design df = 7
_ratio_1: ue91/lab91
--------------------------------------------------------------
| Linearized
| Ratio Std. Err. [95% Conf. Interval]
-------------+------------------------------------------------
_ratio_1 | .1278159 .0040873 .1181511 .1374808
--------------------------------------------------------------
estat effects
_ratio_1: ue91/lab91
----------------------------------------------------------
| Linearized
| Ratio Std. Err. Deff Deft
-------------+--------------------------------------------
_ratio_1 | .1278159 .0040873 1 .866025
----------------------------------------------------------
Note: Weights must represent population totals for deff to be correct when using an FPC; however, deft is
invariant to the scale of weights.
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