Readers of JPGB have already seen the working paper, but Education Next now has the peer-reviewed and published version of Booker, Sass, Gill, and Zimmer’s study of the effect of charter high school on graduation and college attendance. Since you are way ahead of the curve you already knew that attending a charter high school increases the probability that a student will graduate high school and go to college.
The study is so clever because it focuses on students who attended charter middle schools. Some went on to charter high school and some did not. By comparing the two groups Booker, et al reduce the selection bias of choice, since all of the students chose charter schools at least for middle school. But there may still be some selection bias in who chooses to continue in charter high school, so Booker, et al address that with a neato instrumental variable. Some students don’t go on to charter high school because there isn’t one available nearby. Their analysis predicts whether students continue to a charter high school based on the availability of nearby charter options.