More Fun with New Jersey Charter Schools


I love maps. I love GIS software. This is a particularly interesting one related to the shares of children who qualify for free (not free or reduced, but free only, a poorer population) lunch in traditional public schools and in charter schools in Newark. One reason why mapping is useful here is that it is important to compare school demographics with other nearby schools, rather than district average. This map of a portion of Newark pretty much speaks for itself. Click to enlarge the map (to read the free lunch ranges on the key). Clearly, two of the “high performers” among charters – North Star and Robert Treat, have noticeably lower free lunch rates than other schools around them (except for other special schools).(CS indicates Charter School)

Data for this map were acquired from the National Center for Education Statistics Common Core of Data – Public School Universe Survey for 2007-08. These data include latitude and longitude for schools, which may not be perfectly precise. But, they are pretty good overall.

While I’m at it – here are the Jersey City Charters – even more striking differences:

Stepping back a bit to see more charters and taking off the names for clarity, here’s what all of Newark looks like, including some other neighboring towns. Charters have a pink asterisk. Again, smaller circles in lighter shades are lower free lunch schools. There are a few charters that are moderate to higher poverty – similar to many Newark schools (bright green, medium size bubble). However, many charters are the lowest poverty schools to be found. The same is true in the second map below for Jersey City.

Recall from previous posts that Charters are even more different from their neighbors in terms of the numbers of special education and limited English proficient students they serve. Their one saving grace was that they did seem to have relatively high shares of students qualifying for free or reduced price lunch. But, as I have noted in previous posts, they seem, on average to be taking in the less poor among the poor – at least the “model charters” do.  That’s simply not scalable reform. Claims by NJ Charter advocates that these schools are serving the same, high poverty, needy student populations as other schools in their neighborhood are simply wrong – and not supported by any legitimate, fine-grained analysis (and it doesn’t even have to be that fine grained).

Note: One error in other analyses that compare charter school free or reduced lunch rates to district average rates is that those analyses fail to compare by grade level. Few charters in New Jersey are High Schools. High schools on average have lower rates of children qualifying for free/reduced lunch for a variety of reasons – primarily reporting issues. So, if you compare a bunch of elementary schools to a district average which includes high schools, you are likely to show that the elementary schools have higher average free/reduced lunch rate. But it’s not a correct comparison. Charter schools should be compared by grade level to their nearest neighboring and/or sending schools. I’ve not yet run the relevant spatial statistics above.

So, here are a few basic guidelines for future comparisons:

1) compare by relevant grade level because of the way in which subsidized lunch rates shift from elementary to secondary school;

2) while it’s okay to evaluate free and reduced shares, it is also important to slice those shares because children in these categories differ by family background. Looking only at the sum of free and reduced conceals substantial differences in student populations across charters and traditional public schools;

3) compare by location.


Here’s some follow-up data on New Jersey Charter School demographics. Here are the comparisons of disability rates and free lunch shares for Newark and Jersey City Public (Traditional Public) schools by grade level and the disability rates and free lunch shares for Charter schools often cited as outperforming the host district. Note that most claims that these schools outperform the host district use all kids’ test scores, not just general student test scores. So, differences in shares of children with disabilities make a huge difference in proficiency rates. I show this in previous posts on this thread (New Jersey Charter Schools).

Special Education

Note: A knowledgeable reader has informed me that the “0” value for Greater Newark Charter is actually “missing data,” for that year and has assured me that Greater Newark Charter does indeed enroll children with disabilities. At some point, I may get around to updating these analyses.

% Free Lunch

Note that the highest flyin’ charters (Treat and North Star) have substantially lower free lunch shares than the host district in addition to having very low special education rates. Only Marion P. Thomas has a relative high free lunch share, but has very few special education students.

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