Housing affordability

This indicator captures the percentage of households that can find affordable housing. The Department of Housing and Urban Development (HUD) defines housing as affordable if payments are under 30 percent of income. In the 1960s the poverty line was defined by the cost of a minimum diet times three but in the six decades since, the rising cost of housing has required more attention to this variable as a measure of economic well-being
(source: U.S. Census).

Chesapeake watershed region and county-level maps comparing housing affordability scores.

How is it measured?

The U.S. Census five-year American Community Survey contains housing affordability data at the county level. The indicator reflects the combined number of Owner-occupied housing units and Renter-occupied housing units in which houseing costs exceed 30% of the household income. The data of the 197 counties that intersect the Chesapeake Bay watershed boundary are aggregated into regions, used to calculate a z-score, converted to a report card score (which is reversed), and then weighted by population. For the z-score, housing affordability data are compared to the mean and standard deviation of the 197 Chesapeake Bay counties.

For the 2021 report card, data from 2019 was used. The mean of the Chesapeake Bay watershed housing affordability was 26.69%, and the standard deviation was 5.66%.

Threshold Levels

To compare between the four economic indicators, we established a z-score lower and upper bounds (-2.5 to 2.5) that are used to translate a z-score to a 0–100 grading scale—the equation is y = 100 - (20x + 50) where y = the report card score and x = the z-score.