Because charter schools are relatively new institutions — the first American charter school opened in 1992 — little research has been done on the long-term outcomes for students who attended a charter school relative to those who attended a traditional public school.
But with many former charter-school students now in their twenties, Mathematica Policy Research has conducted a study on long-term educational and earning achievements, finding that charter-school students are more likely to have greater educational success and higher earnings than their traditional public-school peers.
In order to account for the possibility that only certain types of students are accepted to charter schools, Mathematica studied only students who had attended charter schools up to the eighth grade, comparing those who continued in charter schools through high school and those who went from eighth grade to a traditional high school. They also controlled for race, gender, family income, and test scores.
Notably, when controlling for test scores, charter-school students still outperform their public-school peers post–high school. “Charter high schools seem to be endowing their students with skills that are useful for success in college and career but that are not captured by test scores,” the study found.