NJ CREDO Report: No Evidence Charter "Success" Can Be Replicated

631 days ago, NJDOE Commissioner Chris Cerf promised a report on charter schools that took into account student demographics "as quickly as is humanly possible." Finally, the CREDO NJ charter report has landed - and with much reformy fanfare:

Study: Charter schools outperform public schools in N.J.

Yeah, we knew that already. The question was never whether or not these schools outperformed public schools; the real question is whether or not charter school successes can be replicated on a large scale.

To that end, I think this is a more relevant headline:

Study: No Evidence Charter School "Success" Can Be Replicated

Why can't "successful" charters be replicated? The CREDO study makes it clear: charters serve fewer children who don't speak English at home and fewer children with special needs than their "feeder" public schools. Look at p.13 in the report - it's right there.

It's also worth noting that even though the CREDO report says charters serve as many children "in poverty" as their feeder public schools, the report's definition of "poverty" is skewed. Bruce Baker has already posted about this:
Now, one technical quibble I have with the CREDO report is that it relies on the free/reduced priced lunch indicator to identify economic disadvantage (and then sloppily throughout refers to this as “poverty”). I have shown on numerous previous occasions that Newark charters tend to serve larger shares of the less poor children and smaller shares of the poorer children. So, it is quite likely that the CREDO matched groups of students actually include disproportionate shares of “reduced lunch” children for charters and “free lunch” children sorted into district schools. This is a non-trivial difference! [gaps between free lunch and reduced lunch students tend to be comparable to gaps between reduced lunch and non-qualified students.] [emphasis mine]
I read the thing at lunch today, so I need to go back and look at it more thoroughly. There's going to be a lot more to say, but here's the bottom line:

Nothing in the NJ CREDO Report contradicts the notion that "successful" charters are "successful" because they serve a segregated population of students.

When you take the children who are less likely to live in extreme poverty, less likely to have a significant learning disability, more likely to speak English at home, and more likely to be a girl (yes, it's true - check out what Bruce says), you're going to get better test scores. It's a peer effect. Suburban parents know all about this because they spend oodles of money to move their families into districts where they can enjoy this very phenomenon.

Much more later.

ADDING: By the way: maybe you heard there was a wee little problem with the test scores CREDO uses and cheating at a "successful" Newark charter. Just thought I'd mention it.