While nearly 63% of owner-occupied housing units are owned free and clear for homeowners age 65 and older, less than 28% of homeowners below retirement age have paid for their homes in full.
This can leave the vast majority of the working population exposed to financial impact during periods of economic turmoil.
Not all areas have equal rates of free-and-clear homeownership, however.
Researchers ranked locations by the share of owner-occupied households without a mortgage, and with positive income and a working-age primary householder (under the age of 65).