The paper has a section listing their controls, including income, poverty rate, race, etc: https://www.nber.org/system/files/working_papers/w35310/w35310.pdf ht

The paper has a section listing their controls, including income, poverty rate, race, etc: https://www.nber.org/system/files/working_papers/w35310/w35310.pdf https://www.nber.org/system/files/working_papers/w35310/w353.... It's on page 11.