# Incorrect codes for PWPUMA
**URL:** https://forum.ipums.org/t/incorrect-codes-for-pwpuma/1894
**Category:** USA
**Created:** [August 28, 2017, 9:27pm UTC](https://forum.ipums.org/t/incorrect-codes-for-pwpuma/1894 "2017-08-28T21:27:00Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@evlatum](https://forum.ipums.org/u/evlatum)
#### Post date: [August 28, 2017, 9:27pm UTC](https://forum.ipums.org/t/incorrect-codes-for-pwpuma/1894/1 "2017-08-28T21:27:00Z")
When opening the “Place of Work: Puma” ([https://usa.ipums.org/usa-action/variables/PWPUMA#codes\_section](https://usa.ipums.org/usa-action/variables/PWPUMA#codes_section)), the ‘Codes’ section refers to a list and maps of 1990 PUMA codes (as opposed to PWPUMA). These codes do not (I think) correspond to each other. This makes it impossible to filter data and, above all, to interpret output as I do not know what the codes in my table under PWPUMA mean.
Please let me know where I can find a list of PWPUMA codes.
Let me know if you require any clarifications. Thank you very much in advance!
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### Author:  [@JeffBloem](https://forum.ipums.org/u/JeffBloem)
#### Post date: [August 28, 2017, 10:26pm UTC](https://forum.ipums.org/t/incorrect-codes-for-pwpuma/1894/2 "2017-08-28T22:26:00Z")
One detail that may help clarify this potential issue is that while [PWPUMA](https://usa.ipums.org/usa-action/variables/PWPUMA#description_section) codes do relate to [PUMA](https://usa.ipums.org/usa-action/variables/PUMA#description_section) codes, PWPUMA provides detail to only 3 digits of the 5-digit PUMA code. Therefore, any PUMAs that use the fourth and fifth digit are aggregated together in PWPUMA.
I hope this is helps.
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### Author:  [@evlatum](https://forum.ipums.org/u/evlatum)
#### Post date: [August 30, 2017, 5:34pm UTC](https://forum.ipums.org/t/incorrect-codes-for-pwpuma/1894/3 "2017-08-30T17:34:00Z")
Dear Jeff,
Thank you for your answer. This did clarify it somewhat, but something remains unclear.
I am researching population differences in New York City between 1990 and 2000. With the information given under the 1990 PUMA codes, the PUMA codes are not named for the neighborhood they represent. It simply says New York City (part) (see [https://usa.ipums.org/usa/volii/puma\_…](https://usa.ipums.org/usa/volii/puma_ny5.shtml)). The only way for me to then find out which specific part it refers to, would be by Census tract but that would obviously be very-time consuming to do for all PUMA codes.
Basically, my question is whether there is a way to compare 1990 and 2000 PUMA codes with each other in an easier way than comparing census tracts on a list?
Best,
Elsa van Latum
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### Author:  [@JeffBloem](https://forum.ipums.org/u/JeffBloem)
#### Post date: [August 30, 2017, 7:07pm UTC](https://forum.ipums.org/t/incorrect-codes-for-pwpuma/1894/4 "2017-08-30T19:07:00Z")
Unfortunately, PUMA codes are not comparable across years. Since PUMAs are typically drawn around areas of 100,000+ residents, they are redrawn with every decennial census as populations shift and grow. This complicates analysis like what you describe above.
We do have some [geographic tools](https://usa.ipums.org/usa/volii/tgeotools.shtml) that may be helpful to you in this work. I’m sorry I don’t have an easier answer or solution for you.