Dear Statalisters,
I'm confused with the following results:
. svyset psu [pweight=weight2007], strata(healtharea)fpc(psusperhealtharea)
pweight: weight2007
VCE: linearized
Strata 1: healtharea
SU 1: psu
FPC 1: psusperhealtharea
.
end of do-file
. svy: tab p29, deff deft
(running tabulate on estimation sample)
Number of strata = 11 Number of obs = 12140
Number of PSUs = 1266 Population size = 12134,139
Design df = 1255
-------------------------------------------------
Any permanent
disability | proportions deff deft
----------+--------------------------------------
0, no | ,8887 -1981 ,9783
1, yes | ,1113 -1981 ,9783
|
Total | 1
-------------------------------------------------
Key: proportions = cell proportions
deff = deff for variances of cell proportions
deft = deft for variances of cell proportions
Why do I get large negative deff values? Deft resembles more what I
was expecting, but it should be the square root of deff and obviously
this is not the case. Do you have any explanation for these results?
Many thanks,
Angel Rodriguez-Laso
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