Diane Ravitch often comments on my stuff and provides a link, and did so with this post. Her readers are more inclined to leave comments than mine, and a discussion about attrition in MA's charters ensued. Stephen B. Ronan, a frequent commenter at Diane's site, left a particularly long one; he also posted here.
With his permission, I am reposting his comment below. I'm doing so because he raises many of the same points I've read in the larger debate over Question #2, and I thought it would be useful to have them all in one place so I can answer them in subsequent posts.
Leave your comments below; mine will follow over the next few weeks, with the exception of the following:
- I didn't provide a link to the MCPSA document in my original post. That was an oversight; regular readers know I post primary source links regularly. I've added the link to the original post.
- Phoenix Charter Academy is, indeed, in Chelsea and not Boston. Again, I corrected that in the original post, and apologize for the error. That said, excluding Phoenix does not substantially alter my original analysis.
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Without providing a link, you quote the Massachusetts Charter Public School Association.
I think this is the full document for those who may be interested:
The segment you quote from states:
"The attrition rate at Boston charters (9.3%) is significantly lower than in BPS (14.2%).
In Gateway Cities, charter attrition rates (6.2%) are lower than Gateway districts (11.4%).
"From 2012-2014, an average of just 82 students left charters and returned to Boston Public Schools, according to BPS numbers – one-tenth of one percent of BPS total enrollment of 57,000."
And you responds to that:
"Yeah, uh... no. Not really."
You claim, properly, that our department of education's "attrition" rate is inadequate to provide a full perspective insofar as it addresses students leaving during the summer. What you may not understand is that the sentence that starts "From 2012-2014" is supplementing the summer attrition figures by citing the number of students who leave charter schools to return to BPS schools not during the summer but rather during the school year. I think the Association's point there is that there's not much such movement during the year relative to summer attrition which is when most of the mobility between sectors occurs.
Our state department of education makes very easily available both summer attrition rates and also measures that show the rates at which students leave during the year. For example, to view the summer attrition and the school year stability rates of one superb charter school and one superb traditional public school, see;
MATCH attrition: http://profiles.doe.mass.edu/attrition/default.aspx?orgcode=04690000&fycode=2015&orgtypecode=5&
MATCH stability: http://profiles.doe.mass.edu/mobility/default.aspx?orgcode=04690000&fycode=2015&orgtypecode=5&
Nathan Hale attrition: http://profiles.doe.mass.edu/attrition/default.aspx?orgcode=00350243&fycode=2015&orgtypecode=6&
Nathan Hale stability: http://profiles.doe.mass.edu/mobility/default.aspx?orgcode=00350243&fycode=2015&orgtypecode=6&
You write: "If charter schools shed kids year after year -- especially if those kids are low-performing -- then their vaunted performance advantages are in question, particularly when compared to public district schools that aren't losing students."
Yes, but in fact the evidence demonstrates that charter schools in this area shed considerably fewer kids than public district schools.
I guess you recognize that may well be the case so move swiftly on to change the subject:
"What we really need to consider is whether the students moving out of charter schools are being replaced at rates equal to the replacement rates for students moving out of public district schools."
Your conclusion there is correct: there's far less backfill in the charter sector.
You write: "Every independent charter school in Boston had a higher cohort attrition rate in 2014 than BPS as a whole."
Is this a specifically New Jersey use of the phrase "cohort attrition rate"? I find it difficult to locate a definition in the academic research literature that combines what is normally considered to be attrition (loss of students) with backfill (gain of students) and calls the merged product "attrition". Though I do see it used that way by both you and Bruce Baker and in New Jersey.
In respect to what may constitutes a "cohort" in respect to individual schools in Boston, it appears that you blend members of multiple entering classes, and of multiple cities. For example, you write:
"In the case of City on a Hill and Phoenix, their 2011 freshman class shrank by more than half by the time they were seniors."
Phoenix doesn't have a school located in Boston. Perhaps you are thinking of the Phoenix charter school not too far away in the city of Chelsea. But given the nature of the school's specialization it makes it doubly hard to justify comparing it with a traditional public school in Boston:
"The school she founded, Phoenix Charter Academy, was conceived as an alternative school for students who had given up on traditional high school, or who felt that their schools had given up on them. As it celebrates its 10-year anniversary this week, it remains a haven for students who thought they might never finish high school."
As for City on a Hill, you omit the implications of this, from its annual report: "There is no social promotion at City on a Hill. 100% of students promoted to the next level in each subject demonstrated mastery of the school’s common-core aligned college prep curriculum by earning 70% or above on written and oral proficiencies."
Presumably as a consequence of that policy City on a Hill has extremely front-loaded grade level retention. The 9th grade class enrollments you examine merge students who are newly starting out and others who are repeating the grade. That distorts any attempt to compare 9th grade and 12th grade enrollment figures to measure attrition.
Massachusetts grade-level retention reports can be found here:
Looking at Appendix B for 2015-2016, one finds for City on a hill the following grade-level retention rates:
9th 10th 11th 12th
27.8 3.3 3.2 7.4
In the past, in the several messages here, you and I discussed whether such a front-loaded grade-level retention pattern skews the results you and your NJ colleagues try to portray:
I continue to believe it does.
The one clearly valid point you make, not a novel one, is that there's less backfill at charter schools here in Massachusets charter schools than at traditional public schools. I'd be interested to see you debate with Michael Petrilli on whether or not that's helpful:
You write: "Is it really worth expanding charters and risking further injury to BPS when the charter sector appears, at least at the high school level, to rely so heavily on cohort attrition?"
Further injury? Could you explain what you meant by that? This has what has been transpiring at BPS in parallel with the growth of charter schools:
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ADDING: Ronan also left this comment at Ravitch's site:
To save us some back and forth, I would suggest that in your response you also consider the material referenced here in respect to attempts to ascribe high test scores at charter schools to attrition:
And both of these documents in respect to hypothetical financial injury to BPS schools:
The latter, which is brand new, states: “In 2016, charter enrollment had the effect of increasing per-pupil spending in district schools by approximately $85 million statewide.”
It has both strengths and weaknesses and you may find it, more generally, worth addressing together with the Brookings study.
You may find this useful: http://www.doe.mass.edu/research/reports/2016/02CharterReport.pdf
Finally, if you have time and space, you may wish to consider how passage or failure of our Q2 may impact likelihood of passage by the voters in 2018 of our millionaire’s tax proposal: http://www.bostonmagazine.com/news/blog/2016/05/17/what-is-millionaire-tax-massachusetts/