Housing costs are going up, up, up for those in the country who can least afford it. (iStock)

The widening gap between wealthy and lower-income households is among the issues expected to dominate political discussions during the 2020 election season. A recent study by Apartment List researchers evaluated the impact of housing costs on income inequality. The study found that incomes are growing fastest for the top tier but that housing costs are growing fastest for families at the bottom range of incomes. Households with incomes in the top 25 percent have seen their housing costs fall, while those with incomes in the bottom 10 percent have seen housing costs — including mortgage payments and rents — rise the most.

Income inequality rose in 45 of the top 50 metro areas. According to the study, Philadelphia has the greatest disparity between its rich and poor residents, while New Orleans has witnessed the greatest inequality growth over the past 10 years.

In the Washington area, households at the 90th percentile earned 10½ times more than those at the 10th percentile in 2017.

When comparing Washington-area residents with the rest of the country, housing costs for those earning more than the national median have decreased by 2 percent. Housing costs for those earning less than the national median, on the other hand, have increased 6 percent.

Nationwide, the gap between renters and homeowners is also widening. Even though the median income of renters has risen over the past decade, rents have also been steadily rising. At the same time, monthly housing costs for homeowners have fallen, primarily because of lower mortgage rates.

For the full report, go to apartmentlist.com/rentonomics/housing-markets-and-income-inequality.