"Diversity" cont.

Following up on the diversity index post from last week, more on the WNYC story about tract 754 in Midwood being the "least diverse neighborhood in the city."

One problem with this contention is that a single census tract is almost never a "neighborhood." Now, there are some cases where you can make the argument that a neighborhood falls within a single census tract: Co-op City, Broad Channel, Breezy Point, and City Island come to mind, for instance. But tract 754 is definitely not a "neighborhood." In fact, the article references several things outside the tract to try and demonstrate the character of the neighborhood, such as the synagogues within walking distance, and the kosher bagel shops and travel agencies advertising trips to Israel on the commercial strip about 5 blocks away. So let's analyze the larger neighborhood picture to see if it's really the "least diverse neighborhood in the city."


View Midwood in a larger map

In red, above, is Brooklyn Census Tract 754, which has a diversity index of 1. In blue is tract 754, plus every tract that borders it (748, 750, 752, 756, 758, 760). This isn't meant to be the borders of "Midwood," it's just meant to give an example of a reasonable geographical area that could be called a "neighborhood" which centers on tract 754. This lets us see how diverse tract 754's "neighborhood" is.

Running the diversity index on the larger area, it ends up at 27*. And if you include an additional two tracts to the west, which encompass the commercial strip WNYC article describes in the article, it ends up even higher at 32.

Now, 27 is still not very high, especially for New York City, whose diversity index as a whole is 78.5, or for Brooklyn, which scores a 74, or even for New York State, which scores a 62**. But it is still far from extreme. For instance, it's a score as high or higher than 8 states (New Hampshire, Vermont, Montana, North Dakota, Iowa, West Virginia, Kentucky, and tied with Wyoming). It's also a higher score than several other places in New York that are considered "neighborhoods," like Howard Beach (23), Gerritsen Beach (21), Broad Channel (19), Manhattan Beach (10), and Breezy Point (7).

For those curious, these are all predominantly white neighborhoods. There are also predominantly African-American neighborhoods, all in Central Brooklyn and Southeast Queens, that I can assume would also score lower than the "Midwood" area I aggregated (there are no predominantly Hispanic or Asian neighborhoods that even come close to Midwood's score, although there is one tract in Chinatown that scores a 24). But what you would call a "neighborhood" in those areas is made up of many more census tracts than the neighborhoods referenced above, which are made up of 3 tracts at most and are generally just one or two, and more than I can do a quick and accurate back-of-the-envelope calculation with. For instance, a reasonable definition of "St. Albans," would be about 15 separate tracts, and for "East Flatbush" would be about 30. For what it's worth, I'm almost certain St. Albans, Cambria Heights, Laurelton, and East Flatbush would all score lower than 27.

There are also some other predominantly white neighborhoods made up of several census tracts, like Borough Park, which would score lower than 27. And in addition, there are several areas - both predominantly white and predominantly African-American - of at least seven census tracts (the same amount as the "Midwood," area I aggregated), but which only make up part of a neighborhood, where this is true as well.

The real point to this exercise is to demonstrate that much of the conversation around the neighbohoods of New York City is heavily dependent on the details of the geography you use. There is no real objectively "correct" geography when it comes to "neighborhoods" in New York, but it's important not to be loose with the term either. The WNYC article reads as claiming that Midwood is the least diverse neighborhood in New York (which is demonstrably untrue), and you have to really examine the article with much closer attention than I believe it is fair to expect a lay reader to do in order to realize that this might not be the case.

Neighborhoods: Midwood
Tracts: B748, B750, B752, B754, B756, B758, B760

*I should note that I calculate the diversity index slightly differently from the most commonly used calculation, which is USA Today's. Specifically, I include "other race" in the base calculation. In the neighborhoods I analyzed, this doesn't have an effect of more than a point or two difference at most. 

** I should also note comparing the diversity index across different sized geographies is not really a good comparison. Especially at very small geographies, it breaks down. For instance, the vast majority of houses in America have a diversity index of 0, as everyone in the household is usually of the same race. An area's diversity index should really be compared across other similar sized geographies, in this case about 18,000 people.