Lessons from New York City’s Most Effective Charter Schools

by Reihan Salam

Harvard economist Roland Fryer has a new Hamilton Institute report on the practices that separate the most effective New York city charter schools from the least effective, and he offers a policy proposal designed to apply these lessons to in conventional public schools:

Our analysis demonstrates that input measures associated with a traditional resource-based model of education—class size, per-pupil expenditure, the fraction of teachers with teaching certification, and the fraction of teachers with an advanced degree—were not related to school effectiveness in our sample.

In fact, schools with more certified teachers have annual math gains that are 0.043 standard deviations lower than other schools. Schools with more teachers with a master’s degree have annual English language arts (ELA) gains that are 0.034 standard deviations lower. Schools with smaller class size, higher per-pupil expenditure, more teachers with teaching certification, and more teachers with an advanced degree actually tended to have lower student achievement.

In stark contrast, five practices—more human capital or teacher feedback, data-driven instruction, high-dosage tutoring, increased time on task, and a relentless focus on high academic expectations—were consistently found in higher- achieving schools. Together, these five practices explain roughly half the difference in effectiveness between charter schools.

Controlling for the other four practices, schools that give formal or informal feedback (more human capital) ten or more times per semester have annual math gains that are equal to 0.6 more months of school and annual ELA gains that are equal to 0.55 more months than other schools. Schools that tutor students at least four days a week in groups of six or fewer have annual ELA gains that are equal to 0.5 more months than other schools. Schools that add 25 percent or more instructional time to the average New York City traditional public school’s time have annual math gains that are equal to 0.625 more months than other schools. Schools that prioritize high academic and behavioral expectations for all students have annual math gains that are equal to 0.55 more months and ELA gains that are equal to 0.375 more months than those schools that do not prioritize those expectations. …

Armed with these correlates of charter school effectiveness, we cannot simply wait for the expansion of successful charter schools. At their current rate of growth, it will take more than a hundred years for high-performing charter schools to educate every student in the country. For these benefits to reach the students who need them most, the United States will need to take the innovations from charter schools that have proven effective and apply them to the traditional public schools that serve most students.

Fryer calls for an effort to spread these practices to benefit the 3 million students attending the worst-performing public schools in the U.S., which he estimates would have a marginal cost of $2000 per student or $6 billion in total. It’s not clear, however, that a spending increase is the only way to implement such a program, e.g., reforming teacher compensation and allowing for somewhat larger class sizes might free up enough resources to finance high-dosage tutoring. Regardless, Fryer’s report merits close attention.