# Link ASEC before 1989

**URL:** <https://forum.ipums.org/t/link-asec-before-1989/1547>\
**Category:** CPS\
**Created:** [January 20, 2017, 5:53pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547 "2017-01-20T17:53:00Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![lionup](https://avatars.discourse-cdn.com/v4/letter/l/da6949/32.png) [@lionup](https://forum.ipums.org/u/lionup)\
**Post date:** [January 20, 2017, 5:53pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547/1 "2017-01-20T17:53:00Z")

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How can I link individuals across ASEC samples before 1989? CPSIDP and HRHHID only starts from 1989. Thanks.

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**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:** [January 20, 2017, 6:29pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547/2 "2017-01-20T18:29:00Z")

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The IPUMS-CPS team has plans to extend the variable [MARBASECIDP](https://cps.ipums.org/cps-action/variables/MARBASECIDP#codes_section) to pre-1989 samples. This will allow also for the extension of [CPSIDP](https://cps.ipums.org/cps-action/variables/CPSIDP#codes_section) to pre-1989 samples. Unfortunately, we don’t anticipate that MARBASECIDH will be available until the end of 2017 at the earliest. In the meantime, you can try to replicate the creation of MARBASECIDP and CPSIDP based on the documentation found in this [working paper](https://cps.ipums.org/cps/resources/linking/4.workingpaper16.pdf). Based on previous work on this task, we know that you’ll need to prune the ASEC samples for duplicates prior to merging across years and that you’ll probably need to include AGE, SEX, and RACE as linking keys.

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**Author:** ![lionup](https://avatars.discourse-cdn.com/v4/letter/l/da6949/32.png) [@lionup](https://forum.ipums.org/u/lionup)\
**Post date:** [January 20, 2017, 6:42pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547/3 "2017-01-20T18:42:00Z")

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Dear Jeff,

Thanks you so much.

According to the paper, I think we need HRHHID to replicate MARBASECIDP and CPSIDP. However HRHHID is also missing in the samples before 1989. Is there a way to have HRHHID?

Best

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**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:** [January 23, 2017, 3:12pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547/4 "2017-01-23T15:12:00Z")

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It turns out that the origional linking keys are currently unavailable on IPUMS and will be released with the next data release. In the meantime, you can check out the attached paper by Madrigan and Lefgren that should help with linking the origional varialbes with IPUMS data. Sorry for any inconvenience.

[madrigan\_lefgren\_200.pdf](https://forum.ipums.org/uploads/short-url/79JC59iEefH7iRjWWPITtimz8ML.pdf) (129 KB)

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**Author:** ![lionup](https://avatars.discourse-cdn.com/v4/letter/l/da6949/32.png) [@lionup](https://forum.ipums.org/u/lionup)\
**Post date:** [January 23, 2017, 3:17pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547/5 "2017-01-23T15:17:00Z")

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Dear Jeff,

Thank you so much. Do you know when is the next data release?

Best wishes

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**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:** [January 23, 2017, 3:20pm UTC](https://forum.ipums.org/t/link-asec-before-1989/1547/6 "2017-01-23T15:20:00Z")

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I don’t see an officially scheduled CPS data release yet, but it shouldn’t be long as the CPS project releases data fairly frequently.