More than half of Madison's renters are considered cost-burdened, but the percentage has been falling slightly for the last five years.
And in 2014, Madison's share of renters who pay 30 percent or more of their household income toward housing fell below the national average.
The drop, however, may be more indicative of an introduction of more high-income renters than a decrease in the actual number of cost-burdened renters, said Matt Wachter, the housing initiatives specialist for Madison's Community Development Authority.
Rental website Apartment List released a report Wednesday highlighting cost-burdened rates around the country, using U.S. Census Bureau American Community Survey data between 2007 and 2014.
In 2014, 51 percent of Madison renters were considered moderately or severely cost-burdened compared to 51.8 percent for the country as a whole and 47.4 percent for Wisconsin. In Milwaukee, the figure was 57.7 percent, and in Green Bay, 53.6 percent.
Moderately cost-burdened renters include those who pay between 30 and 49 percent of their household income toward housing, while a severe cost burden represents those paying 50 percent or more.
In Madison, more than three in 10 renters were in the latter category in 2014, paying at least half of their income toward housing.
That Madison has a higher percentage of severely cost-burdened renters than the state or the nation and a lower percentage in the moderate class has been largely consistent during the eight-year period studied by Apartment List.
Wachter said that while the percentage of renters who are cost-burdened may have dropped recently, it's likely that the total number in that situation has not.
He said the city has added a lot of high-income households in the last few years, which could serve to pull down the cost-burdened percentage.
Apartment List data scientist Andrew Woo said Madison's median renter income had been fairly flat between 2007 and 2013 before spiking in 2014 with a 10 percent jump over 2013.
In a long view, the national percentage of cost-burdened renters is up significantly now compared to the early 2000s, Woo said.
"One of the interesting things that we noted was it's not really a problem that's isolated to the big cities," he said. "It's a problem that's fairly widespread."
Madison has seen a shift in housing preference toward renting, according to a market rate rental housing report. Along with that, the Madison area's rental vacancy rate has been between 2 percent and 3 percent, a level that the city considers unhealthy and leads to higher rents as the supply-and-demand balance shifts toward landlords.
Madison needs to build more than 1,000 apartment units a year just to keep up with growing demand, Wachter said, and it has been surpassing that number recently.
Many of those units have been in luxury downtown projects, however. Madison, meanwhile, has committed $20 million over five years to an affordable housing fund to help finance developments with lower-cost units.
Those efforts to add 1,000 affordable rental units aren't reflected in the cost-burdened percentages, Wachter said, because the first units won't open until 2016.