After studying rent increases in New York City, NYU’s Furman Center has released a report that labels 15 neighborhoods as “gentrifying” — out of 55 total.

In this case, gentrification is defined as areas that were relatively low income in the 1990s, but since have experienced high rent growth.

“The term ‘gentrification’ is often used to describe a number of different aspects of neighborhood change. We wanted to create a definition that allowed us focus on dramatic rent growth, which is the change that is of greatest concern in lower-income neighborhoods,” Ingrid Gould Ellen, faculty director of the NYU Furman Center, said in a press release.

While rents have increased across New York City, according to the Furman Center, the rise has particularly burdened low- and moderate-income households in all neighborhoods, with “the share of recently available rental units affordable to low-income households declin[ing] sharply in gentrifying neighborhoods between 2000 and 2010-2014.”

In the 15 neighborhoods classified as gentrifying, between 2000 and 2014 (for the end of the period of study, the report draws on data from the American Community Survey 2010-2014), average rents increased by 30 percent. Topping the list, the Williamsburg and Greenpoint neighborhoods saw average rent increase by 78.7 percent between 1990 and 2014, compared to 22.1 percent in the city as a whole.

Even the nine neighborhoods identified in the report as non-gentrifying — low income in 1990 and low income now — saw a 16.1 percent average rent increase between 2000 and 2014, having experienced a drop in average rents in the 1990s. Neighborhoods across the city saw an increase in the number of households that are rent burdened, with non-gentrifying neighborhoods bearing the brunt.

(From NYU Furman Center's “State of New York City’s Housing and Neighborhoods in 2015”)

Incomes in the 15 gentrifying neighborhoods identified in the report — including Central Harlem, the Lower East Side, Astoria and Sunset Park — also went up, while incomes in the remainder of the city’s neighborhoods largely did not. Between 1990 and 2014 average household income in the gentrifying neighborhoods rose by about 14 percent, compared to an 8 percent decline in non-gentrifying neighborhoods like East New York and Coney Island, and steady incomes in higher-income areas like the Upper West Site and Fort Greene.

(From NYU Furman Center's “State of New York City’s Housing and Neighborhoods in 2015”)

The gentrifying neighborhoods are defined not only by their starker rent increases, but also by their demographic shifts. They’ve seen greater growth than non-gentrifying areas in their share of residents who are young adults, college-educated, and living alone or with roommates. While the rest of New York has seen a decline in the percentage of the population that is white, the gentrifying neighborhoods saw an increase.

“As demand grows and neighborhoods become more economically and racially integrated, longtime residents may benefit from new neighborhood amenities, reduced crime rates and higher housing values,” said Ellen in a statement. “However, rising rents threaten the long-run diversity of these communities.”

Despite accounting for only 26 percent of the city’s population, the gentrifying neighborhoods also absorbed one-third of all housing units added in New York City from 2000 to 2010. But increased stock didn’t contribute to affordability: The share of recently available rental units affordable for low-income households declined sharply in gentrifying neighborhoods between 2000 and 2014.

The 15 neighborhoods identified as gentrifying today are the same ones bled of their populations during a mass exodus of NYC residents between 1970 and 1980. Over 800,000 people left that decade, with nearly 80 percent departing from the low-income neighborhoods that would later gentrify. Those neighborhoods also lost over 128,000 units of housing during the 1970s and 1980s. Higher-income neighborhoods regained their 1970 population levels by 1990; non-gentrifying neighborhoods did so by 2000. But in 2010, the population in gentrifying neighborhoods was still 15.8 percent lower than it was in 1970.