# Does IPUMS have the Census Bureau-created SERIALNO variable for ACS data?

**URL:** <https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217>\
**Category:** General\
**Created:** [June 17, 2013, 5:27pm UTC](https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217 "2013-06-17T17:27:00Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![tonyschick](https://avatars.discourse-cdn.com/v4/letter/t/db5fbb/32.png) [@tonyschick](https://forum.ipums.org/u/tonyschick)\
**Post date:** [June 17, 2013, 5:27pm UTC](https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217/1 "2013-06-17T17:27:00Z")

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I read that SERIAL is a variable unique to IPUMS and should not be confused with the serial numbers created by the Census Bureau. But I’d like to be able to merge an IPUMS extract with some data I have that contains the Census Bureau SERIALNO. Is it possible to get that variable with an extract?

Apologies if this is addressed elsewhere. I browsed around and searched but didn’t find it.

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**Author:** ![Brandon\_Trampe](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Brandon\_Trampe](https://forum.ipums.org/u/Brandon_Trampe)\
**Post date:** [June 17, 2013, 6:04pm UTC](https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217/2 "2013-06-17T18:04:00Z")

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Unfortunately, it is not currently possible to obtain the Census Bureau SERIALNO in an IPUMS extract. However, there may still be a solution.

While we’ve only verified that this works in some of the ACS samples, it may be possbile to merge the Census Bureau SERIALNO onto the IPUMS files. The files share a common sort order, so you can perform a sequential merge within your stats package to add SERIALNO onto the IPUMS files. Of course, you’ll want to ensure that the file structure and treatment of vacant units are consistent between the two files before performing the merge.

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**Author:** ![tonyschick](https://avatars.discourse-cdn.com/v4/letter/t/db5fbb/32.png) [@tonyschick](https://forum.ipums.org/u/tonyschick)\
**Post date:** [June 17, 2013, 6:12pm UTC](https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217/3 "2013-06-17T18:12:00Z")

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Thanks for the answer, Brandon. I’m working with the 2009-2011 ACS. By chance do you know if this will work using that dataset?

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**Author:** ![Brandon\_Trampe](https://avatars.discourse-cdn.com/v4/letter/b/35a633/32.png) [@Brandon\_Trampe](https://forum.ipums.org/u/Brandon_Trampe)\
**Post date:** [June 17, 2013, 7:08pm UTC](https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217/4 "2013-06-17T19:08:00Z")

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I believe it should work for the 2009-2011 ACS file.

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**Author:** ![tonyschick](https://avatars.discourse-cdn.com/v4/letter/t/db5fbb/32.png) [@tonyschick](https://forum.ipums.org/u/tonyschick)\
**Post date:** [June 17, 2013, 9:24pm UTC](https://forum.ipums.org/t/does-ipums-have-the-census-bureau-created-serialno-variable-for-acs-data/217/5 "2013-06-17T21:24:00Z")

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OK great. If that doens’t work I suppose I could also attempt to create a unique identifier using other common variables and merge on that. Thanks very much for your help.