Charter schools boost graduation rates and college attendance in Florida and Chicago, according to a Mathematica study reported in Education Next. All the students in the study had chosen to attend a charter middle school: Some went on to a charter high school and others chose a traditional public high school.
Controlling for key student characteristics (including demographics, prior test scores, and the prior choice to enroll in a charter middle school), students who attend a charter high school are 7 to 15 percentage points more likely to earn a standard diploma than students who attend a traditional public high school. Similarly, those attending a charter high school are 8 to 10 percentage points more likely to attend college. Results using an alternative method designed to address concerns about unmeasured differences between students attending charter and traditional public high schools suggest even larger positive effects. Our main results are comparable to those of some studies which find that attending a Catholic high school boosts the likelihood of high school graduation and college attendance by 10 to 18 percentage points.
Charter eighth graders who chose a charter high school were more at risk of dropping out than those who went on to a non-charter school, the study found.
BTW, the Public Charter School Dashboard is a handy source of stats.