Hi, Aidan. I am also not an expert on this, but if you sign up with IPUMS and use their forum, you can get expert help from the staff there. I've not looked at how income is calculated in ACS in a long time, but sometimes the results of income surveys can be a bit troublesome. For instance, a business owner who is rather wealthy might report a very low figure for income of the started a new business that is still not making money or if they had a bad year. So, you may want to poke around to learn how "income" is calculated or how the income question is worded. Again, IPUMS discussion forums are a great place to go for this.
Keep in mind that many households are made up of individuals and young people, who will have lower incomes (including graduate and professional students in a university city), or older individuals, who may have fixed incomes. Speaking of households, you phrased your question about individuals, but you may want to focus on households. Again, many households are just one person, but a married couple or multi-generational household could afford more housing than individual income implies. Make sense?
Hope that helps!
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Douglas R. Hess, PhD
APTA
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Original Message:
Sent: 05-20-2026 01:55 PM
From: Mark Mather
Subject: Am I messing up here?
Hi Aidan,
I'm not an expert in this topic, but the lopsided distribution seems plausuble, assuming a lot of Grand Rapids households have modest incomes.
One thing you might consider: the ACS has a variable called GRPIP that already calculates rent as a share of income for you, and the CB publishes housing cost burden tables from it. Would those tables help answer your question? This alternative method only makes sense if you're estimating housing cost burden rather than constructing a synthetic affordability distribution.
If you stick with your custom calculation, make sure you've filtered out group quarters households, which can skew the results in some cities. Also, note that many households may have zero or negative income, which could be contributing to the distribution you're seeing.
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Mark Mather
Associate VP
PRB
Original Message:
Sent: 05-20-2026 12:45 PM
From: Aidan Rozema
Subject: Am I messing up here?
Hello all! I am a student who is still learning the ropes of using federal data. I have been trying to construct a distribution of what people in Grand Rapids, Michigan could reasonably afford in rent using the 5-year American Community Survey (sourcing data from IPUMS) by calculating HHINCOME / 12 * 0.3. I know that many Americans have low-incomes, but I keep ending up with this really lopsided distribution. I was wondering if anyone has tried something similar, and if they have any tips. I'm new to this, so I have the sinking feeling that I messed up somewhere...
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Aidan Rozema
Student Researcher
University of Michigan
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