# Supplemental Poverty Measure

**URL:** <https://forum.ipums.org/t/supplemental-poverty-measure/4356>\
**Category:** CPS\
**Created:** [October 25, 2021, 7:46pm UTC](https://forum.ipums.org/t/supplemental-poverty-measure/4356 "2021-10-25T19:46:14Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Monica\_Fisher](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@Monica\_Fisher](https://forum.ipums.org/u/Monica_Fisher)\
**Post date:** [October 25, 2021, 7:46pm UTC](https://forum.ipums.org/t/supplemental-poverty-measure/4356/1 "2021-10-25T19:46:14Z")

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I am interested to calculate the share of supplemental family unit resources that is derived from various sources, such as earnings, public assistance, private assistance. For such purpose, I first tried to verify for that the sum of INCTOT across SPMFAMUNIT members is equivalent to SPMFTOTVAL. Working with the 2020 dataset, I obtain averages that differ by a couple thousand dollars. I’m writing to ask what I might be doing wrong.

Thank you.

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**Author:** ![Ivan\_Strahof](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.ipums.org/ivan_strahof/32/626_2.png) [@Ivan\_Strahof](https://forum.ipums.org/u/Ivan_Strahof)\
**Post date:** [November 1, 2021, 9:00pm UTC](https://forum.ipums.org/t/supplemental-poverty-measure/4356/2 "2021-11-01T21:00:19Z")

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The sum of [INCTOT](https://cps.ipums.org/cps-action/variables/INCTOT#description_section) across [SPMFAMUNIT](https://cps.ipums.org/cps-action/variables/SPMFAMUNIT#description_section) members is equivalent to [SPMFTOTVAL](https://cps.ipums.org/cps-action/variables/SPMFTOTVAL#description_section). You might be getting different values if you aren’t accounting for observations that are not-in-universe (NIU). [INCTOT values of 999999999](https://cps.ipums.org/cps-action/variables/INCTOT#codes_section) do not represent earnings but rather observations that are NIU. The [Universe tab for INCTOT](https://cps.ipums.org/cps-action/variables/INCTOT#universe_section) shows that these are cases of children under 15 years of age. Dropping these NIU (INCTOT = 999999999) and Missing (INCTOT = 999999998) cases should produce estimates for INCTOT across SPMFAMUNIT that are equivalent to SPMFTOTVAL.