Charter Schools, An Exchange: Part VI (Final)
This is the last installment of an exchange about charter schools between myself and Dmitri Mehlhorn.
Part I: Mehlhorn's opener.
Part II: My reply.
Part III: Mehlhorn's response.
Part IV: My second reply.Part V: Mehlhorn's second response.
Part VI (this post): My final reply.
I hope everyone has found this enlightening. My sincere thanks to Dmitri Mehlhorn for engaging me in this debate.
* * *
In his final installment in this debate, Dmitri Mehlhorn posed five questions to me. Here are my responses.
Q: "Jazzman, why don’t TPS (traditional public schools) test results go down as charters expand?"
A: We don't really know that they don't. But even if they don't, there are other pernicious effects for district schools when charters expand.
As I explained in Part II, the evidence we have about the effects of charterization on neighboring public district schools is quite limited. The Texas study Mehlhorn cited earlier (Booker et. al, 2008) shows a small positive effect for hosting districts; however, the proliferation rate of charters was quite small. In that study, most districts had well under 5 percent of their students in charters, so it's reasonable to think any "cream skimming" -- the process where charters take only those students who are more likely to thrive under a "no excuses" model -- had only a small influence on the district schools.
What happens when the charter enrollments get up to 40 percent, as they are in
