Friday, December 14, 2007

Why NYC Private School Kids Drink Frappuccinos

Edudiva and others asked for more analysis on NYC private school attendance (prior posts here and here). Below is a map displaying the proportion of K-12 kids that go to private school by neighborhood. Thanks to my friend "soupa prof," this map makes it easier to see which NYC neighborhoods send high proportions of K-12 kids to private school. (Click on the map below to enlarge.)

NYC K-12 Private School Enrollment by Census Tract, 2000
In the map below, soupa prof also marked every Starbucks location in Manhattan with a green dot. If we adopt education policy's traditional logic - i.e., correlation equals causation - we can conclude that going to private school starts kids down the crooked path of frappuccino consumption.

Manhattan K-12 Private School Enrollment and Starbucks Locations

Or! Maybe Starbucks locate in affluent neighborhoods - as Ms. Frizzle has noted, peppermint mochas and crack are about the same price. Thanks to skoolboy, here's a graph plotting the percentage of students attending private school in a given census tract against median family income. The graph shows a remarkably strong relationship between the two; the correlation is .85.

In short, the Benjamins explain the frap addictions of our well-heeled NYC kids.


Harringtonian said...

While I'm sure your observation regarding the correlation between income and private school attendance in Manhattan is correct, I would be skeptical of such a direct relationship in boroughs such as Brooklyn. For example, I suspect the high concentration of private school children in the southern end of District 14 (Williamsburg) or the northern end of District 20 (Borough Park) is less attributable to a higher concentration of rich folks and is more likely a reflection of the large Orthodox Jewish populations there.

I wonder if your data mavens might consider ascertaining if my hypothesis is correct?

skoolboy said...

I'm not quite skilled enough to identify the census tracts in these neighborhoods, but I can tell you that the correlation between median family income and percent K-12 students enrolled in private schools is indeed much lower for the 760 census tracts in Brooklyn than for the tracts in Manhattan -- .37 vs. 85. There's a bunch of tracts with relatively low median incomes but high rates of private school enrollment, and some of these may have a high concentration of Orthodox Jews. One part of the Manhattan pattern does hold true in Brooklyn as well: high-income tracts tend to have high rates of private school enrollment. In the 16 Brooklyn census tracts with a median family income of over $100K, 55% of the school-aged kids attend private schools. In the 68 Brooklyn census tracts with a median family income of less than $20K, 18% of the school-aged kids attend private schools. I bet that if I were able to adjust for religion, this difference would be even more dramatic.

skoolboy said...

Sorry, I forgot to add this. Harringtonian's post implies a slight modification to Eduwonkette's heading for her post: "Why NYC Private School Kids Drink Frappuccinos -- but Not with Meat"

EduDiva said...

I started looking at the St. Louis County districts (and will post on it sometime this week) and think that other factors such as a strong Catholic tradition are just as important.

Love the Starbucks correlation!

Thequeen said...

I cannot give praise to any advertisement promoting Starbucks as the source. I can see this with Seattles Best or Millstone or whatever NYC might offer but when Starbucks was asked to donate Coffee to the Soldiers,they said no! They said they did not believe in the war(who cares) It was for our very young men our brothers,friends,cousins,sisters,daughters and sons made to go there,it was for them,not The War.
So we that support our troops who have no choice but to be there promote company's that support them also.(Starbucks did not).

Anonymous said...

To The Queen,

I wanted to let you know that all the Starbucks here in the California Monterey area donate coffee to the troops.


Anonymous said...

Awesome,great to hear that because here in the Seattle area several notes of complaints for boysotting them went across the internet. May it was one store and they made a big issue out of it but I will pass the word to those I know that signed a petition about this. Thankyou.

Anonymous said...

What a nightmare sorry about my typos not enough coffee yet,lol.