# How to make appropriate comparisons between ACS including GQ and those that not capture GQ?

**URL:** <https://forum.ipums.org/t/how-to-make-appropriate-comparisons-between-acs-including-gq-and-those-that-not-capture-gq/474>\
**Category:** USA\
**Created:** [April 1, 2014, 3:18pm UTC](https://forum.ipums.org/t/how-to-make-appropriate-comparisons-between-acs-including-gq-and-those-that-not-capture-gq/474 "2014-04-01T15:18:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![lexvillar](https://avatars.discourse-cdn.com/v4/letter/l/5daacb/32.png) [@lexvillar](https://forum.ipums.org/u/lexvillar)\
**Post date:** [April 1, 2014, 3:18pm UTC](https://forum.ipums.org/t/how-to-make-appropriate-comparisons-between-acs-including-gq-and-those-that-not-capture-gq/474/1 "2014-04-01T15:18:00Z")

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I calculated the higher education enrollment rates at state level using ACS from 2001 to 2012. I know that since 2006, the ACS captures population living in group quarters. Given the topic that I am analysing (enrollment in higher education of multiple population groups), how can I make appropiate comparison between ACS pre and post 2006? Should I work only with information from individuals living in households, i.e., those with gq equal 1 and 2?

Also, how appropiate is to make comparisons between ACS 2001-2004 and ACS from 2005 and beyond given the substantial differences in sample size?

Thank you for your help.

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**Author:** ![grover](https://sea1.discourse-cdn.com/flex019/user_avatar/forum.ipums.org/grover/32/5_2.png) [@grover](https://forum.ipums.org/u/grover)\
**Post date:** [April 1, 2014, 8:35pm UTC](https://forum.ipums.org/t/how-to-make-appropriate-comparisons-between-acs-including-gq-and-those-that-not-capture-gq/474/2 "2014-04-01T20:35:00Z")

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It is a good idea to be cautious when comparing the 2000-2004 ACS samples to the 2005-onward ACS samples. As you noted, one of the most potentially disruptive differences between the two sets of samples is the exclusion of Group Quarters from the 2000-2004 ACS samples. It may be a good idea to remove Group Quarters from the later samples, as you suggest, to increase the consistency of the sample universe. I would recommend trying a few analyses with and without the Group Quarters exclusion to try to gauge the impact. The 2000-2004 ACS samples are also smaller than the 2005-onward samples (as noted on the [Samples page](https://usa.ipums.org/usa/sampdesc.shtml#us2000d)), which makes them less likely to capture smaller sub-populations and specific geographic areas. These differences may impact your analyses, but ultimately it is up to you to decide if these differences are acceptable for your study.

I hope this helps.