In more precise terms, half of the public schools (928) have black and Hispanic enrollments of at least 90.1 percent — the median. A quarter (464) are at least 95.9 percent black and Hispanic.
Because so many schools are clustered just north of the “racially representative” zone, the slightest demographic nudge — in some cases, the addition of a single white or Asian kid — could drop a cusp school into the zone, thus contributing its entire enrollment toward the 50,000-student goal. If the 105 schools currently between 90.1 percent and 92 percent black and Hispanic fell to 90 percent (moving an average of just one percentage point), the city’s goal would be reached.
Let’s say it happens. What would this allow us to claim?
Well, for the 50,000 students who move inside the zone, the demographic shift of their schools would likely be imperceptible. More importantly, it would tell us nothing about the racial diversity experienced by the 65 percent of students still outside of the zone. As a small percentage of schools inch closer to the mean, the poles could drift even farther apart.
In other words, the city could reach its goal even if the system at large were to become more segregated.
To illustrate this concept, imagine Lebron James’ goal next season is to score within five points of his points-per-game average more often — say, three more times than he did this season. He could achieve his goal while having an even more scattered overall scoring distribution. Measuring the point totals that fall within an arbitrary zone provides no information about point totals outside of the zone.
Now, before proposing a better metric, I must first comment on the term “racially representative,” which is inaccurate and misleading. Most of the schools in the city’s “racially representative” zone have at least two races that are heavily underrepresented or overrepresented. P.S. 28 in Queens is 89.9 percent Hispanic but meets the definition because it has zero black students. P.S. 398 in Crown Heights meets it, too, even though it has just two white and four Asian students (13 percent of the school identifies as “other”).
Why would the city choose such a flawed term? My guess is that they thought “racially representative” would evoke thoughts of diversity, as opposed to segregation, a word the mayor hesitates to use in reference to schools. But, no matter how they label it, what they are really assessing is the degree to which black and Hispanic students are racially isolated — which is exactly what school segregation researchers measure.
So, how to fix the goal? Focus on moving the median.
As I mentioned, the median percentage of black and Hispanic students in city schools is 90.1 percent. Anything done to move the median toward the mean (67.8 percent) would result in a less segregated system overall. Setting targets related to the distance between the mean and the median would also control for possible demographic shifts that static goals, such as the current one, do not take into account.