# Merge IPUMS CPS prior 2006

**URL:** <https://forum.ipums.org/t/merge-ipums-cps-prior-2006/1230>\
**Category:** CPS\
**Created:** [March 7, 2016, 5:59pm UTC](https://forum.ipums.org/t/merge-ipums-cps-prior-2006/1230 "2016-03-07T17:59:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![salga010](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@salga010](https://forum.ipums.org/u/salga010)\
**Post date:** [March 7, 2016, 5:59pm UTC](https://forum.ipums.org/t/merge-ipums-cps-prior-2006/1230/1 "2016-03-07T17:59:00Z")

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Hi there,

I am trying to merge individuals between different years of the March CPS. After 2004 I use the variables

mish sex lineno hrhhid hrhhid2

to merge and it works very well, merging the expected number of infividuals considering the rotation of the panel.

However, when I move back of 2005, the variable hrhhid2 is not available anymore and I cannot find a set of variables that help me to merge let say, march CPS individuals in 2005 to those in 2006, or even 2004 to 2003 data sets.

Is there anyway to merge those series?

Many thanks!

S

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**Author:** ![Tim\_Moreland](https://avatars.discourse-cdn.com/v4/letter/t/f1d935/32.png) [@Tim\_Moreland](https://forum.ipums.org/u/Tim_Moreland)\
**Post date:** [March 10, 2016, 8:24pm UTC](https://forum.ipums.org/t/merge-ipums-cps-prior-2006/1230/2 "2016-03-10T20:24:00Z")

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Prior to 2005, you will want to use [HUHHNUM](https://cps.ipums.org/cps-action/variables/HUHHNUM#codes_section), in place of HRHHID2, to link ASEC samples. Unfortunately, this is not guaranteed to give you a unique match across samples, as the ASEC includes an oversample of households from adjacent months. IPUMS-CPS is currently working on a variable called MARBASECID to facilitate linking across ASEC samples (see this [previous answer](https://forum.ipums.org/t/is-it-possible-and-how-to-merge-march-cps-with-asec-cps/908/1)). In the meantime, you can use person-level characteristics such as SEX, AGE, and RACE to help improve your match rate.

Hope this helps.

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**Author:** ![salga010](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@salga010](https://forum.ipums.org/u/salga010)\
**Post date:** [March 14, 2016, 5:51pm UTC](https://forum.ipums.org/t/merge-ipums-cps-prior-2006/1230/3 "2016-03-14T17:51:00Z")

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Hi Tim,

yes it helped. Now I was able to match up to 1996 but before that seem to be impossible. Anyway. Looking forward for the new variable.

Thanks!

Sergio