Brookland Manor, an affordable housing complex in the District that has tried to evict poor residents in order to redevelop amid the city’s economic boom. (Michael S. Williamson/The Washington Post)

After a decade of major demographic changes in the District,starting with rapid gentrification in the mid-2000s, the number of poor families burdened by rising rents has grown sharply, with many thousands more people now paying crushing percentages of their meager incomes for housing, according to a new study.

The report, from the nonprofit D.C. Fiscal Policy Institute, focuses on a significant portion of residents who have been left behind by the District’s economic rebirth since the early 2000s, when the city emerged from a prolonged financial crisis.

The study also partially quantifies the impact of the District’s shortage of affordable housing, especially on the most impoverished families.

For example, in 2004, when an influx of newcomers, mainly affluent young professionals, was just beginning to heat up the D.C. rental market, half of the city’s poorest cohort of families was “extremely housing-cost burdened,” meaning that housing costs consumed more than 50 percent of their incomes.

By 2014, when the poorest cohort numbered 43,000 families, the study says, 26,600 of them, or 62 percent, were extremely burdened. And many were coping with rents that amounted to far more than 50 percent of their incomes. Of the 26,600 households, more than 18,000 faced housing costs in excess of 80 percent of their incomes, according to the report’s author, housing researcher Claire Zippel.

“We’ve seen in recent years that the higher-income, higher-skilled people in this city are doing really well,” Zippel said in an interview. “There have been a lot opportunities and growth created at that level, which is great for the city in many ways.”

However, she said, “at the same time, it’s important not to lose sight of the fact that we still have a 17 percent poverty rate, and there’s still a significant amount of people for whom the economic recovery has not been evident at all.”

The study examines the housing costs for the poorest D.C. households, with annual incomes of less than $32,000 for a family of four. Among those “extremely low-income” families, most earn far less than $32,000 -- the average income is just $16,000, Zippel said.

The nation’s capital weathered the post-2007 recession better than most cities and attracted hordes of well-educated, well-salaried new residents who could afford luxury-scale rents. But “the incomes of extremely low-income households has remained flat over the past decade, reflecting stagnant pay for workers without a college degree” and the fixed incomes of elderly and disabled residents, Zippel wrote.

In an interview, she said that several market forces related to gentrification have put mounting financial pressure on extremely low-income renters.

“There’s less market-rate housing that’s affordable for people at this income level because rents are rising across the board,” she said. “They’re rising in gentrifying neighborhoods; we’re seeing that all over the city. And they’re rising over time in neighborhoods that aren’t gentrifying yet, because the population is going up and so is the demand.”

She also cited the financial temptations faced by some private owners of rent-subsidized apartment complexes for low-income residents.

Those landlords provide affordable housing under contracts with the U.S. Department of Housing and Urban Development. In once-poor neighborhoods that have gentrified, owners of apartment complexes for low-income tenants have let their federal contracts expire, preferring to take advantage of increased market prices.

“As the real-estate market heats up, landlords have to decide whether to stay in subsidized affordable housing or go to market rate,” Zippel said. “And it’s definitely fair to say we’ve seen an acceleration of landlords going to market rate. If they’re in a really hot area, it’s very difficult and expensive to preserve that affordable housing.”

Meanwhile, amid rising rents, she said, “we know a lot of workers in extremely low-income households who are severely rent-burdened are in the service industry. We know their wages have been stagnant over the past 10 years. These are people who don’t have access to a lot of the new jobs that have been created in the city.”

Although the D.C. Housing Authority operates several dozen public housing complexes that are largely immune to rent-related market forces, the complexes are virtually full, with about 42,000 households on the waiting list, the agency said.

Of the city’s 43,000 extremely low-income households, 25 percent are headed by parents, typically a single mother with two children, Zippel said. She said childless low-wage workers make up 37 percent of the households, elderly residents comprise 8 percent, and disabled people account for 30 percent.

As for the 26,600 households in that cohort whose housing costs are more than half their incomes: 8,600 of them pay 51 percent to 80 percent of their incomes for housing and 18,600 pay more than 80 percent, according to the study.

“Despite the seeming impossibility of dedicating all or almost all income to rent, many of the District’s poorest residents do have to try to get by with such high housing burdens,” Zippel wrote. “Households in this situation have little or no money left after making rent each month and many go through cycles of getting behind on rent.”

At other times, they go without such basic necessities as healthy food and utilities.

Zippel said the problem also “reflects the city’s stark racial inequality.” Although African Americans comprise about 48 percent of the D.C population, they account for 91 percent of the extremely low-income residents who are rent-burdened, she said. Nearly all of the remaining people in that category are Latinos.

“Such high housing cost burdens cause serious problems,” Zippel wrote. “Families living in unaffordable housing are at a higher risk of being evicted, moving frequently, living in crowded or substandard conditions, or becoming homeless.”

She noted, “When households are forced to move, it often starts a downward spiral, as families frequently lose belongings, lose their job, have to move in with family or friends, or move to neighborhoods of higher crime and worse-performing schools.”