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.
>>
>>
>
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