I don't see a problem with it, in theory at least. The drivers licenses has a precedent as being used as a carrot--it came be taken away for child support, crimes, and drunk driving. If it means that a high school student is more likely to go on and get a diploma, then let them do it.
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.
