In their recently published study, “What Can We Learn from Charter School Lotteries?” Julia Chabrier, Sarah Cohodes, and Philip Oreopoulos take a closer look at students who have and have not been chosen to enroll in a charter school.  Lotteries provide the kind of random assignment of individuals to “treatment” and “control” groups so highly valued by social science researchers because it eliminates population bias and other empirical sticky wickets.

Overall, Chabrier and her colleagues found that each year of enrollment at a charter school “increases math scores by 0.08 standard deviations and English/language arts scores by 0.04 standard deviations.”  While these are impressive gains, there was a great deal of variation in the performance of charter school students.

For example, disadvantaged students in urban neighborhoods with very poor performing schools who attended “no excuses” charter schools were the one group of students who consistently benefited from charter school attendance.  Consistent with a growing body of research, charter schools that adopted a “no excuses” model, which establishes high behavioral standards and academic expectations for students, appeared to have the most success for disadvantaged children fortunate enough to be selected in the charter school lottery.

Specifically, the authors found that the presence of an “intensive tutoring” program had the strongest relationship to academic gains.  Class size, per pupil expenditures, or teacher certification were largely irrelevant.  I repeat.  There was no statistically significant relationship between student performance and class size, per pupil expenditures, or teacher certification.  Although “intensive tutoring” made the most difference, researchers point out that the tutoring variable may be a proxy for factors that were not necessarily accounted for in the study.

North Carolina has a number of “no excuses” charter schools.  In contrast to the Chabrier, Cohodes, and Oreopoulos study, however, disadvantaged students in both urban and rural “no excuses” charter schools in the state have a strong record of raising student performance and academic growth.

KIPP Gaston College Preparatory in rural Northampton County is one of the oldest and most successful “no excuses” charter schools in North Carolina.  Gaston Prep serves mostly low-income African American middle school students and almost 80 percent of their students are eligible for a free or reduced-price lunch.  Yet, on independent Measure of Academic Progress (MAP) tests, 84 percent of students made at least one year of academic progress in math and 78 percent of students achieved similar gains in reading.  Gaston Prep’s scores on North Carolina tests are consistently higher than schools in the region and earned a solid B school performance grade last year.

KIPP Charlotte opened in 2007, KIPP Halifax College Preparatory opened in 2014, and KIPP Durham College Preparatory opened in 2015.  Similar to KIPP Gaston College Preparatory, these schools serve mostly disadvantaged students.  KIPP Charlotte and KIPP Halifax Prep each earned C school performance grades but both had tremendous academic growth, which regrettably accounts for only a fraction of the performance grade.  First-year results from KIPP Durham will be released later this year.

That is not to say that only charters that adopt a “no excuses” approach will be successful.  Schools in the TeamCFA network, for example, use what many would consider “traditional” instructional and behavioral management approaches and still have been among the top performing schools in the state, particularly for students who live in rural and economically distressed communities.  In fact, Thomas Jefferson Classical Academy in Forest City has been ranked as one of the best schools in the nation.  In their 2016 Best High Schools publication, US News & World Report ranked Thomas Jefferson #4 in North Carolina high schools, #43 in charter high schools nationally, #124 in the rankings of all high schools in the nation.

The bottom line is that there are no magic formulas to charter school success.  While we know that “no excuses” charter schools work for certain student populations, other approaches may work equally well.  Perhaps the most appropriate public policy response is to not dictate that charter school use (or don’t use) certain operational, instructional, or behavioral management practices but instead allow them the freedom to operate in whatever way benefits the students they serve.