# Missing Standard Error for 5% 2000 estimates using Cluster/Strata

**URL:** <https://forum.ipums.org/t/missing-standard-error-for-5-2000-estimates-using-cluster-strata/1327>\
**Category:** USA\
**Created:** [June 1, 2016, 3:48am UTC](https://forum.ipums.org/t/missing-standard-error-for-5-2000-estimates-using-cluster-strata/1327 "2016-06-01T03:48:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![skye](https://avatars.discourse-cdn.com/v4/letter/s/f475e1/32.png) [@skye](https://forum.ipums.org/u/skye)\
**Post date:** [June 1, 2016, 3:48am UTC](https://forum.ipums.org/t/missing-standard-error-for-5-2000-estimates-using-cluster-strata/1327/1 "2016-06-01T03:48:00Z")

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I am attempting to calculate standard errors for the 5% 2000 PUMS data file. Specifically, I am attempting to caclulate the average household size for certain dwelling characteristics. I have collapsed the original rectangular dataset such that each observation indicates a household. For each household, I have indicated to stata to keep the first observed value for the number of person records, the strata variable, the cluster variable, and hhwt.

As indicated by the user guide, I svyset my data with the following command: svyset cluster [pweight=hhwt], strata(strata)

However, when I attempt to caclulate the mean value of NUMPREC, I receive a single point estimates with no standard errors and no 95% confidence intervals. In addition the following note is included: “Missing standard error because of stratum with single sampling unit.”

I’m not quite sure why I am getting this error. Is it something to do with the Indiana subsample perhaps being too small? Or perhaps I have erred in a command. Any help would be appreciated. Thank you.

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**Author:** ![grover](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.ipums.org/grover/32/5_2.png) [@grover](https://forum.ipums.org/u/grover)\
**Post date:** [June 2, 2016, 7:27pm UTC](https://forum.ipums.org/t/missing-standard-error-for-5-2000-estimates-using-cluster-strata/1327/2 "2016-06-02T19:27:00Z")

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I believe the issue you are seeing can be resolved by using the subpop() option for the Stata svy command as described in the “Syntax for Subpopulation Analysis” of the [Analysis and Variance Estimation with the IPUMS](https://usa.ipums.org/usa/complex_survey_vars/userNotes_variance.shtml) page. You can also use the over() option for the mean command to get estimates with Std. Err. values like so:  
svy: mean numprec, over(statefip)

I hope this helps.