That's an unknown but I can see the possible positive rationale. It seems to me that if someone is dropping out, generally it's a statement about the parents more than the child and sometimes they drop out to care for an ailing family member or to earn money to help the family. Granted:It doesn't make for much of a bright future but drunk driving and child support are real criminal carrots. This isn't.
I'd be surprised if the drop out rate was effected by more than a tiny percentage of kids who are dropping out to support an ailing family member or to support the family financially. I'm sure it happens but probably not to a significant degree. But as a freedom issue, a driver's license just isn't a right. It might actually have some positive effect in decreasing drop out rates. However if I were a SC legislator, I would want to see some sort of hard data to that effect before I would vote for it.