Steve,
The second stage units are not also stratified. My -svyset- command is:
svyset psu [pw=weight], strata(rural) fpc(npsu) || ssu, fpc(nssu) || hh, fpc(nhh)
and the singletons appear in ssu.
Do you have any other suggestions?
Cheers
Michael
On 13/01/2010, at 9:58 AM, [email protected] wrote:
> If I understand you, Michael, the second stage units in your PSUs are
> also stratified. If those second-stage strata are ordered in any way
> (geographically, for example), I suggest that you assign the singleton
> to a neighboring stratum.
>
> -Steve
>
> On Tue, Jan 12, 2010 at 4:51 PM, Michael Begg <[email protected]> wrote:
>> Hi Steve,
>>
>> I have heard back from Stata Technical and it is not a bug.
>>
>> I made a mistake below, my survey is actually a 3 stage design and the singletons were in the second stage. My apologies for this.
>>
>> So I guess I now have three options
>>
>> 1) Drop the observations that are causing the problem - in this case 426 out of a sample of 5,964.
>> 2) Add one of the three singleunit() option to my -svyset- command.
>> 3) Reassign the sampling unit to another appropriately chosen stratum or in my case, reassign the ssu to a different psu.
>>
>> For 2), does anyone have any recommendations on which option to choose?
>> For 3) how would I go about reallocating the 18 ssu to a new psu?
>>
>> Cheers
>>
>> Michael
>>
>>
>> On 08/01/2010, at 8:22 AM, [email protected] wrote:
>>
>>> It looks like a bug, and I suggest that you send it to Technical
>>> Support. Be sure to show them (and us) what you see if you run:
>>>
>>> svydes hhsize, single gen(bad_strat)
>>>
>>> -Steve
>>>
>>> On Thu, Jan 7, 2010 at 2:33 AM, Michael Begg <[email protected]> wrote:
>>>> Hi,
>>>>
>>>> I am working on a data from a 2 stage survey design with 2 stratum. When I calculate the mean of hhsize, the standard error is missing as shown below.
>>>>
>>>>
>>>> svy: mean hhsize
>>>> (running mean on estimation sample)
>>>>
>>>> Survey: Mean estimation
>>>>
>>>> Number of strata = 2 Number of obs = 5964
>>>> Number of PSUs = 194 Population size = 16041309
>>>> Design df = 192
>>>>
>>>> --------------------------------------------------------------
>>>> | Linearized
>>>> | Mean Std. Err. [95% Conf. Interval]
>>>> -------------+------------------------------------------------
>>>> hhsize | 4.656919 . . .
>>>> --------------------------------------------------------------
>>>> Note: missing standard error because of stratum with single
>>>> sampling unit.
>>>>
>>>>
>>>
>>> *
>>> * For searches and help try:
>>> * http://www.stata.com/help.cgi?search
>>> * http://www.stata.com/support/statalist/faq
>>> * http://www.ats.ucla.edu/stat/stata/
>>
>>
>> *
>> * For searches and help try:
>> * http://www.stata.com/help.cgi?search
>> * http://www.stata.com/support/statalist/faq
>> * http://www.ats.ucla.edu/stat/stata/
>>
>
>
>
> --
> Steven Samuels
> [email protected]
> 18 Cantine's Island
> Saugerties NY 12477
> USA
> 845-246-0774
>
> *
> * For searches and help try:
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*
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