Blogger Jersey Jazzman is an experienced teacher and graduate student at Rutgers, where he has learned how reformers play games with data. He is better than they are and can be counted on to expose their tricks.

In this post, he blows away the myth of the “success” of Boston charter schools.

The public schools and the charter schools in Boston do not enroll the same kinds of students, due to high attrition rates in the charters (called Commonwealth charter schools).

He writes:

“As I pointed out before, the Commonwealth charter schools are a tiny fraction of the total Boston high school population. What happens if the cap is lifted and they instead enroll 25 percent of Boston’s students? What about 50 percent?

“Let’s suppose we ignore the evidence above and concede a large part of the cohort shrinkage in charters is due to retention. Will the city be able to afford to have retention rates that high for so many students? In other words: what happens to the schools budget if even more students take five or six or more years to get through high school?

“In a way, it doesn’t really matter if the high schools get their modest performance increases through attrition or retention: neither is an especially innovative way to boost student achievement, and neither requires charter school expansion. If Boston wants to invest in drawing out the high school careers of its students, why not do that within the framework of the existing schools? Especially since we know redundant school systems can have adverse effects on public school finances?”

Conclusion: Jersey Jazzman opposes Amendment 2, which would lead to an unsustainable growth in charter schools, free to push out the students they don’t want.