It both. Engaged parents and an ability to be selective lead to higher graduation rates. It's a decent system to complement public education.Not exactly. They have better graduation rates because the parents who send their kids to private school actually act like parents. They all take their kids' education seriously and don't treat the school like free daycare. I'm not saying that all public school kids' parents are like that, just enough of them to make the school environment counterproductive to learning. All too often, school kids are out of control and the faculty is powerless to do anything. That isn't the case in private school.