# Replicate weights and confidence intervals **URL:** \ **Category:** CPS\ **Created:** [February 5, 2018, 5:33pm UTC](https://forum.ipums.org/t/replicate-weights-and-confidence-intervals/2147 "2018-02-05T17:33:00Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![khimm](https://avatars.discourse-cdn.com/v4/letter/k/aeb1de/32.png) [@khimm](https://forum.ipums.org/u/khimm)\ **Post date:** [February 5, 2018, 5:33pm UTC](https://forum.ipums.org/t/replicate-weights-and-confidence-intervals/2147/1 "2018-02-05T17:33:00Z")
I am attempting to use the replicate weights to calculate confidence intervals for means and frequencies of CPS/ASEC variables in SAS using PROC SURVEYMEANS and PROC SURVEYFREQ procedures. However, when I do so, I am getting confidence intervals that seem unreasonably broad (e.g. +/- 3% for variables with 10,000 unweighted respondents). Please let me know if there are common misinterpretations of this replicate weights or programming errors that can lead to this issue. Thanks! ---
**Author:** ![JeffBloem](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.ipums.org/jeffbloem/32/40_2.png) [@JeffBloem](https://forum.ipums.org/u/JeffBloem)\ **Post date:** [February 5, 2018, 9:06pm UTC](https://forum.ipums.org/t/replicate-weights-and-confidence-intervals/2147/2 "2018-02-05T21:06:00Z")
I am not sure what version of SAS you are using, but note that [this document](https://cps.ipums.org/cps/resources/repwt/Use_of_the_Public_Use_Replicate_Weight_File_final_PR.doc), provided by the US Census Bureau, provides SAS code that can be modified to create the replicate weight file. If you haven’t already, this may be a helpful resource. Also note that in general, the standard error of a particular estimate tends to increase with the use of replicate weights. More information about IPUMS CPS replicate weights is [available here](https://cps.ipums.org/cps/repwt.shtml).