• Philadelphia is one of America’s most diverse cities — and one of the most divided.

• It has almost equal numbers of Black residents…

• …and white residents…

• …and sizable numbers of Hispanic and Asian residents. There are also many residents of other and multiple races.

• Consider Northwest Philadelphia, where sharp lines remain between where white and Black residents live.

• Just over two miles apart are zip codes with very different demographics — and social outcomes.

  19118

  19138

  67% white

  Race

  91% Black

  4.3%

  Unemployment rate

  13.3%

  $123,780

  Median family income

  $50,554

  5.7%

  People in poverty

  23.2%

• Social outcomes often correspond to where people live. And this city of neighborhoods is often strongly segregated by race.

As Linda Bell walked down a street in East Mount Airy, where she’s lived all her life, she pointed out what she calls “my” playground, in a part of the Northwest Philadelphia neighborhood that remains largely Black. A paved walkway overgrown with vegetation leads to a neglected basketball court.

She contrasts that with the better-kept “white” playground nearby, where she recalls not being welcome as a child.

Mount Airy, which lies directly between the 19118 and 19138 zip codes, has long won national recognition for its level of racial integration. In the 1950s and 1960s, residents banded together to halt white flight from the neighborhood.

But Bell, 69, who sits on the board of the East Mount Airy Neighbors community group, doesn’t experience a model of integration. As she walked, she counted the boarded-up and visibly vacant homes on her side of the neighborhood and contrasted them with the intact houses in adjacent Chestnut Hill.

There are clear divides, said State Rep. Chris Rabb, whose Northwest Philadelphia district encompasses Mount Airy and the white and Black neighborhoods just beside it.

“We rarely see people west of Stenton [Avenue] crossing into east of Stenton,” he said, referring to a line that divides wealthier and poorer parts of the area, “and that’s largely a racial dynamic.”

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That persistent residential segregation makes Philadelphia one of the country’s most racially divided cities. An Inquirer analysis of 2020 Census data shows that almost no matter which groups you look at, and using multiple ways of measuring segregation, Philly is one of the most stubbornly divided metropolitan areas in a rapidly diversifying and increasingly integrated country:

• The eight-county region’s Black-white residential segregation is the fourth highest among the 20 biggest metropolitan areas, as defined by the Census Bureau. The region is the sixth-most segregated between Hispanic and white residents.

• Among the 30 biggest cities, Philadelphia is second only to Chicago in its level of residential segregation between Black and white residents, according to data from Brown University. Between Hispanic and white residents, it’s the sixth-most segregated.

• Considering every U.S. county that has at least 10,000 people and a Black population of at least 5%, Philadelphia is more segregated than 94% of them.

• While residential segregation between Black and white residents has declined nationwide over the last several decades, it’s happened much slower in Philadelphia. The city’s position near the top of rankings of segregated places has stayed almost the same since 1980.

“We have nothing to be proud of,” said John Landis, an urban planning scholar at the University of Pennsylvania.

The complexities of segregation

Segregation is a complex topic with a fraught history. That complicates any effort to comprehensively measure and understand it.

The Philadelphia of today was partly produced by legally enforced segregation — not here, but in the South, which triggered the Great Migration of African American workers to Northern cities.

While housing wasn’t legally segregated in the North, de facto segregation was reinforced by policies like redlining — which discouraged banks from lending to buyers in Black neighborhoods — and federal policies and restrictive deeds that kept Black residents out of white areas.

Some racial enclaves also popped up because people chose to live with people like themselves — immigrants, for example, often cluster near others who speak their language and understand their culture.

The census provides 10-year snapshots of the resulting segregation.

Its accounting of every person in America and where they live allows us to measure residential segregation. Those data don’t reflect other aspects of people’s lives: where they travel, with whom they work, or who their friends are.

Analyzing segregation also requires making decisions about race. The Inquirer’s analysis divides everyone into five non-overlapping groups:

• All Hispanic residents, regardless of race

• White residents who aren’t Hispanic

• Black residents who aren’t Hispanic

• Asian and Pacific Islander residents who aren’t Hispanic

• Residents of all other races, including Native Americans, or of two or more races

Some valuable nuance inevitably gets lost.

For example, that would count Barack Obama, the first Black president, not as Black but as multiracial. And Afro-Latinos — for example, the rapper Cardi B — would be grouped with the Hispanic population, despite also being Black.

Still, The Inquirer’s analysis and others’ make clear that Philadelphia is highly segregated. And research shows that has deep implications.

As in Northwest Philadelphia, residential segregation is strongly correlated with differences in income, poverty, health care, and other metrics.

“Where you live determines so much about your life chances,” said Doug Massey, a Princeton University sociologist who studies segregation. “A lot of what's holding Black progress back is the fact that they live in really bad neighborhoods with really poor opportunity structures.”

Chronic underinvestment has left many such neighborhoods with worse-performing schools, food deserts, higher crime, fewer jobs, and poorer transit connections. The less wealthy part of Rabb’s two-tone House district sees a lot more gun violence, abandoned cars, illegal dumping, and nuisance businesses, he said: “We see far less of that in the more affluent parts.”

As complicated as the causes and effects of residential segregation are, actually measuring it can be simple.

One of the most commonly used measures is called the “dissimilarity index,” which gives a region a 0-to-100 score by comparing the demographics of the whole area (like Philadelphia) with those of its constituent parts (like neighborhoods or city blocks).

In a highly segregated city, some neighborhoods might be very Black and others very white, making for a high “dissimilarity” between the smaller neighborhoods and the larger city. In a less segregated place, individual neighborhoods have a mix of residents, making their demographics more similar to the overall area.

Philly is highly segregated — no matter how you measure it

Philadelphia has the second-highest dissimilarity index among the 30 biggest cities, and the 12th highest out of hundreds that a team led by John Logan at Brown University examined.

The Inquirer compared Philadelphia with all the other counties in America with more than 10,000 people and at least 5% of whom are Black. Philadelphia’s dissimilarity index was higher than 94% of them. A similar comparison looking at Hispanic residents shows Philly to be more segregated than 96% of counties.

And while Philadelphia’s suburban counties are much less segregated, the city’s segregation pulls the whole area’s dissimilarity score upward, placing the region behind only the New York City, Chicago, and Detroit metropolitan areas.

It’s not just the dissimilarity index that paints a dire picture.

Another measure of segregation, the “isolation index,” essentially measures how likely residents are to have a neighbor of a different race. Philly has the sixth-highest Black isolation score among major cities, meaning Black Philadelphians mostly have Black neighbors.

Dissimilarity and isolation measure the composition of individual neighborhoods. Landis, the Penn professor, also applied another metric, “Moran’s I,” that looks at how those neighborhoods are distributed throughout a county.

On that metric, Philadelphia ranks particularly poorly for Hispanic residents, with the third-highest score among major counties; for Black residents, Philly is 10th highest. This means Hispanic and Black residents are clustered in neighborhoods that tend to border other Hispanic and Black neighborhoods. By contrast, New York’s Hispanic population is also highly concentrated, but those neighborhoods are distributed all across the city.

How neighborhoods change

Experts are worried these numbers aren’t declining fast enough. The pace of residential desegregation has been glacial, and it’s even more sluggish today than it was decades ago.

The level of segregation “just keeps dripping slowly downward,” said Logan, the Brown sociologist.

Compare the Philadelphia and Dallas metro areas. Both had Black-white dissimilarity scores of about 78 in 1980. But over the last 40 years, Philly’s has declined only 10 points, while Dallas’ has declined by 25.

And social scientists have noticed another problem: While desegregation is moving in the right direction, the social problems associated with residential segregation mostly have not.

“The disparity in the income level of the neighborhoods where [Black residents] live has remained high, and almost the same,” Logan said.

Part of the apparent paradox could come down to how desegregation is taking place. In general, it’s true that more integrated neighborhoods have provided better opportunities for historically disadvantaged groups — but not if the problems that go with segregation follow the people who are moving.

For example, Logan’s research has found that Black-white desegregation can occur when Black residents move into a previously white neighborhood after Hispanic or Asian residents do. That no longer triggers white flight the way it once did. But there’s a caveat: These newly integrated neighborhoods also tend to be more disadvantaged in the first place.

“Blacks are getting into more neighborhoods with whites, but it's not better neighborhoods with whites,” Logan said. “It's just that it's the neighborhoods where the whites who are there are worse off. So it's not exactly equalizing.”

And even when residents of segregated neighborhoods move, it isn’t necessarily voluntary.

“A lot of Black [residents’] moves are forced moves, from being evicted, or are some external economic shock,” said Massey, the Princeton sociologist.

That’s because segregation can be both a symptom and a cause of a larger problem: the historical and ongoing exclusion of Black Americans from building generational wealth through home ownership.

There’s also gentrification. Neighborhoods don’t just integrate when Black people and other people of color move to previously white areas; it can also happen in reverse.

But gentrification’s impact is unclear — Landis said it integrates cities only slightly, while Massey said it “doesn't affect the overall patterns and levels of segregation.”

What has to change

Landis said fair housing laws passed at the end of the 20th century made a sizable dent in residential segregation by making mortgages more accessible to Black and Hispanic buyers — making it easier to leave segregated neighborhoods.

That trend was most pronounced in affordable, rapidly growing suburbs in the South and West, which led to faster integration than in the Midwest and Northeast.

But that could also help explain the slowdown in integration since the Great Recession, Landis said: “A lot of young people are living with their parents, and a lot of the people who bought those homes with cheap mortgage money [lost] them in foreclosure.”

Emily Dowdall, policy director at Reinvestment Fund, a Philadelphia-based redevelopment nonprofit, said public policy needs to include solutions such as “helping with access to capital for households that don’t have generational wealth” and “addressing zoning to ensure there are a mix of housing options.”

“The city needs to keep investing in all neighborhoods,” she said, “to make sure they can offer the type of amenities that are going to attract different types of households at different types of incomes.”

Whatever the mechanism, increased integration could help equalize the situation Rabb still sees in his district.