# Issue selecting variables

**URL:** <https://forum.ipums.org/t/issue-selecting-variables/4516>\
**Category:** USA\
**Created:** [February 15, 2022, 5:12pm UTC](https://forum.ipums.org/t/issue-selecting-variables/4516 "2022-02-15T17:12:20Z")\
**Posts on this page:** 1\
**Showing post:** 4

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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:** [February 15, 2022, 7:38pm UTC](https://forum.ipums.org/t/issue-selecting-variables/4516/4 "2022-02-15T19:38:15Z")

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PERNUM and other individual-level variables are only preselected if you have other individual-level variables in your cart. However, you only selected HHINCOME and FTOTINC, both of which are household-level variables. Therefore, your extract defaults to only showing households, for which PERNUM is unavailable. If you want to include both individual and household data, you first want to add a person-level variable to your extract. Then, when you’re on the _Extract Request_ screen, select _Data Structure_. This will let you choose whether you want a rectangular (person), hierarchical, or household only data structure. A hierarchical structure will include both household data followed by person-level data for each corresponding household.

 ![Extract Request](https://us1.discourse-cdn.com/flex019/uploads/ipums/original/1X/6d045e03f497cfa1b7d07ad231581302e36a6326.png)  
 ![Data Format](https://us1.discourse-cdn.com/flex019/uploads/ipums/original/1X/75e2a3c98b8708ac679081d7c05de11a9d48a36a.png)

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