# Links to step and bio parents

**URL:** <https://forum.ipums.org/t/links-to-step-and-bio-parents/6778>\
**Category:** TIME USE\
**Created:** [October 3, 2025, 7:46pm UTC](https://forum.ipums.org/t/links-to-step-and-bio-parents/6778 "2025-10-03T19:46:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Pilar\_Gonalons-Pons](https://avatars.discourse-cdn.com/v4/letter/p/5f9b8f/32.png) [@Pilar\_Gonalons-Pons](https://forum.ipums.org/u/Pilar_Gonalons-Pons)\
**Post date:** [October 3, 2025, 7:46pm UTC](https://forum.ipums.org/t/links-to-step-and-bio-parents/6778/1 "2025-10-03T19:46:07Z")

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Hi!

I’m trying to create a variable identifying stepparents. I’m starting with the earlier data 2007-2020 and using pemomtyp/pedadtyp and pelnmom/pelndad.

The issue I’m seeing is that many times the person line number on pelnmom and pelndad seem to be wrong. For instance the pelnmom will have the linenum of a man, not a woman, in the household. This seems to happen a lot, for both step and bio parents. Is there any way to check/correct for these issues?

Thank you!

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**Author:** ![Isabel\_Pastoor](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.ipums.org/isabel_pastoor/32/788_2.png) [@Isabel\_Pastoor](https://forum.ipums.org/u/Isabel_Pastoor)\
**Post date:** [October 4, 2025, 10:49pm UTC](https://forum.ipums.org/t/links-to-step-and-bio-parents/6778/2 "2025-10-04T22:49:31Z")

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Make sure you are referring to the variable [LINENO\_CPS8](http://lineno_cps8/) to identify each parent. PELNMOM and PELNDAD both refer to the line number reported in LINENO\_CPS8, and not [PERNUM](https://www.atusdata.org/atus-action/variables/PERNUM#codes_section).

If you are still seeing issues even when using LINENO\_CPS8, you might also look into [how PELNMOM/PELNDAD are reported](https://www.atusdata.org/atus-action/variables/PELNMOM#description_section). These two variables are reported as is and may need additional cleaning by researchers. In particular, when a child resides with one biological parent and that parent’s cohabiting partner, the child is usually reported to live with only one parent. Researchers can use information on the father’s cohabiting partner ([PECOHAB](https://www.atusdata.org/atus-action/variables/PECOHAB)) to identify those cohabiting stepmothers who are not included in PELNMOM. Married stepmothers are always identified by PELNMOM.

I believe you are aware of the IPUMS-constructed family pointer variables [MOMLOC](https://www.atusdata.org/atus-action/variables/MOMLOC#codes_section) and [POPLOC](https://www.atusdata.org/atus-action/variables/POPLOC#codes_section). See also [MOMRULE](https://www.atusdata.org/atus-action/variables/MOMRULE) and [POPRULE](https://www.atusdata.org/atus-action/variables/POPRULE). You may find these useful as alternatives or complements to PELNMOM/PELNDAD.

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**Author:** ![Pilar\_Gonalons-Pons](https://avatars.discourse-cdn.com/v4/letter/p/5f9b8f/32.png) [@Pilar\_Gonalons-Pons](https://forum.ipums.org/u/Pilar_Gonalons-Pons)\
**Post date:** [October 23, 2025, 9:06pm UTC](https://forum.ipums.org/t/links-to-step-and-bio-parents/6778/3 "2025-10-23T21:06:25Z")

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Thank you, Isabel! Using lineno\_cps8 fixed the discrepancies I was seeing.