NYC's staggering inequality, mapped

(all numbers are in thousands of dollars)

What makes a neighborhood rich or poor?

If you look at the big picture, there's a clear pattern: the wealthy concentrate in the center of the city (lower Manhattan) and the suburbs outside it (Long Island), while the area in between those two--the urban periphary--is home to the working class. Cities across America follow this pattern, which is a result of rich people wanting to live either in the fashionable, exciting downtown areas close to where they work, or in the suburbs with their big houses and quiet, secluded settings.

This pattern also reflects the impact of the shift in the mid-20th century to car-oriented cities: many working-class neighborhoods on the periphary were destroyed by highways being built through them, making them noisy, polluted, and impossible to walk around in. Downtowns were usually considered too important to tear up this way, while the suburbs were built around cars to begin with, so this was never an issue.

The Bronx is a textbook example of the disastrous effects of building highways through a densely populated area that was originally built around public transit. The construction of subway lines there, which allowed people to commute to their jobs in Manhattan, turned the Bronx from rural to urban in just twenty years--its population skyrocketed from 90,000 in 1890 to 420,000 in 1910. Working-class Irish, Italians, and Jews fled the filthy tenements of lower Manhattan for more spacious apartments in the Bronx. In the 1950s, as Black and Puerto Rican migrants flocked to the borough, several highways were built right through it, displacing thousands of residents and turning streets from bustling commercial thoroughfares into barren no-mans-land that divided communities in two. This made the white flight in the Bronx even more severe, and for a time, the borough really was a crack-infested, crime-ridden, decaying hellhole. Dominicans and other immigrants have helped revive the area by solving the problem of underpopulation (which contributes to crime and housing decay) and setting up new businesses, so the Bronx is much safer and more liveable than it used to be. But as the map above shows, the poverty there is still striking, and the 15th Congressional District, which covers the southern part of the borough, is the poorest district in America. That's what happens when people who mainly get around on foot or on public transit still have to deal with the problems caused by highways right in their backyard. NYC's poorest ZIP code is Mott Haven at the southern tip of the Bronx, a mainly Latino neighborhood which is polluted by both highways and industrial areas nearby that leave local residents plagued by asthma and other health conditions.

Each borough has its own pattern. Manhattan is sharply divided between a rich south and a poor north. Queens is mostly middle-class with some wealthy areas on the outskirts. We think of Brooklyn as hip and gentrifying, but a look at the map shows that this is only true for a small portion of it. Most of the borough is still dominated by working-class immigrants and ethnic minorities--Latinos, West Indians, African-Americans, Hasidic Jews, Pakistanis, Russians, and Chinese. Staten Island is mainly middle-class, while Westchester County is a mixed bag. The parts of Long Island shown on this map are incredibly wealthy, although the further east you go, the commute to Manhattan gets longer and as a result the people who live there get less affluent.
The prize for NYC's richest ZIP code goes to 10007, which has a median income of $235k--more than 4x as much as the city as a whole. It's really not surprising, considering that this includes Battery Park City, a series of towers overlooking the Hudson River that are surrounded by tree-covered walking paths and are a short walk away from Wall Street, where many residents work. In fact, many of the city's wealthiest ZIP codes are near the Financial District. Others are in obscenely rich suburbs, like Scarsdale in Westchester County and Great Neck in Long Island, which are dominated by beautiful old houses and quiet tree-lined streets.

The overlap between race, ethnicity, and class

In case you're wondering, yes, there's a very strong correlation between wealth and whiteness. The median household income for White New Yorkers is around $80.3k, compared to $59.4k for Asians, $42.6k for Blacks, and $37.5k for Latinos.  Here's a map of race by ZIP code to compare with the income map:

As you can see, race and class are nearly synonymous in New York. This is especially true in Manhattan, 96th Street acts as the dividing line both between rich and poor and between White and colored. In the Bronx, Riverdale stands out as a wealthy White neighborhood in a working-class Latino borough. In Staten Island, the North Shore stands out for the opposite reason. Brooklyn is in many ways divided into two parallel societies--Whites living in fashionable yuppie neighborhoods in the west, Blacks living further east in what can only be described as ghettos. However, the further south you go, the less synonymous race and class become. South Brooklyn, home to large populations of Hasidic Jews and immigrants from the former USSR, is the only majority-White area on the map that's noticeably poorer than the city average. Similarly, though it's not visible on this map, the Hasidic section of Williamsburg is one of the poorest neighborhoods in all of America.
There are also significant exceptions to the rule in Queens, which is much less segregated than the other boroughs. The most striking outlier is the large swath of affluent Black neighborhoods in the southeast. West Indian immigrants place a strong emphasis on home ownership, so many of them initially settle in central Brooklyn and work their asses off until they have enough to buy a spacious home in Canarsie, Rochdale, St. Albans, or Cambria Heights. The outer reaches of Queens are home to many other middle-class immigrant neighborhoods, like Bayside and Little Neck in the northeast (Chinese and Koreans) or Ozone Park and Richmond Hill in the south (Indians, Indo-Guyanese, and Latinos).
It's noteworthy, though, that Asians, who have the highest median income of any racial group in America as a whole, are considerably poorer than Whites in NYC. In fact, until recently, they had the highest poverty rate of any of the city's racial groups. Among other factors, this is because Asians who come to the US already having money and education tend to settle in affluent suburban areas, while poor Asian immigrants who have to work their way up often start out in working-class areas of cities like New York and San Francisco. Of course, "Asian" is an incredibly broad category, so there's a lot of variation. There are affluent Asian areas, like northeastern and south-central Queens, which are mainly Korean and Indian, respectively. Those groups are quite a bit wealthier than the average New Yorker. Chinese immigrants, on the other hand, live in some of the worst poverty of any group in NYC. That one poor ZIP code in Lower Manhattan? That's Chinatown. The poorest ZIP code in Queens? Flushing.

Latinos are also slightly poorer in NYC than in the rest of the country. Dominicans and Puerto Ricans, two of America's poorest ethnic groups, make up the bulk of NYC's Latino population. The city's large undocumented population is underrepresented in census data, so the median Latino income may be even lower than indicated. Black New Yorkers, on the other hand, are somewhat better off than Black Americans overall, since African and Caribbean immigrants--who are plentiful in New York--tend to be more successful than African-Americans. And unsurprisingly, White New Yorkers are much wealthier than White Americans as a whole--$80k and $61k respectively--since most poor Whites live in rural areas.

Issues with median household income

It's important to note than median household income (MHI) isn't a perfect measure of a family's prosperity. "Household" is an important word here for a few reasons:

1. MHI doesn't take into account family size. Two adults might make the same income, but if one has kids and the other doesn't, the latter will for all intents and purposes have more money. So Brooklyn's Hasidic neighborhoods, where the average woman has seven kids, are probably even poorer than their incomes suggest. The same is true to a lesser extent in Latino areas.
2. MHI doesn't nessecarily correspond to how much someone makes, because it doesn't take into account how many wage earners there are in a household. Lower Manhattan is even richer than it seems, because most people there are young and single, so it's just one person making all that money. Those rich suburbs in Long Island only seem wealthier than lower Manhattan because most households there are married couples with two working adults. Similarly, the high rate of single-parent households probably plays an even bigger role than low wages in the poverty of the South Bronx or northeast Brooklyn.
3. There's a difference between income and wealth. Wealth takes into account the assets you own, such as homes and businesses, while income only counts your wages or salary. So two people could be making the same amount of money, but if one owns a home and the other rents, there's a big difference in how wealthy they are. For example, the MHI for a White family is "only" 1.6x higher than for a Black family, but in terms of median wealth, the gap is much bigger--about 12x as much for Whites. Why? Because, even when you take into account class differences, White people are much more likely to own homes. The reasons are myriad, but the biggest is that for decades, Whites benifited from low-interest mortgages that were largely off-limits to people of colo due to redlining.
4. This is unrelated to MHI, but ZIP codes are not a perfect geographic unit. They sometimes lump very distinct areas together and create a rough statistical average that masks the differences within. So the boundaries of a ZIP code don't neatly line up with the boundary between rich and poor--it's typically more like a grandient. On this map, distinct neighborhoods like South Williamsburg or Hudson Heights are invisible because they're divided between multiple ZIP codes. Still, the map gives a good approximation. If you want to see the micro-level data, check out the same site where I got the information for this map. It's a godsend for demographics nerds like me.