Dear statalisters,
I am using the survey commands in Stata to find some means. I have removed all the stratums in which one psu (primary sampling unit) is detected. I check that there is no stratum with one psu for all my variables by using the svydes command.
I don't have problems to get the invididual means for the individual variables "general" and "producti". However when i want to find the mean of the "general" variable given that "producti" variable is equal to zero i get the message that a stratum with one psu is detected. The "general" variable is continuous, and the "producti" variable is binary.
Any hints will be highly appreciated.
Thanks in advance.
Here is a copy of the output that i get.
svymean general
Survey mean estimation
pweight: empwt_nr Number of obs = 1727
Strata: newstr1 Number of strata = 44
PSU: newpsu1 Number of PSUs = 162
Population size = 1200.4609
------------------------------------------------------------------------------
Mean | Estimate Std. Err. [95% Conf. Interval] Deff
---------+--------------------------------------------------------------------
general | 4.156863 .0044976 4.147957 4.16577 2.432631
------------------------------------------------------------------------------
. svymean producti
Survey mean estimation
pweight: empwt_nr Number of obs = 1727
Strata: newstr1 Number of strata = 44
PSU: newpsu1 Number of PSUs = 162
Population size = 1200.4609
------------------------------------------------------------------------------
Mean | Estimate Std. Err. [95% Conf. Interval] Deff
---------+--------------------------------------------------------------------
producti | .3359512 .0475784 .2417331 .4301693 17.51394
------------------------------------------------------------------------------
. svymean general if producti==0
stratum with only one PSU detected
r(460);
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