None of these methods work. I can give horror stories for each one.

Currently, a school cannot even verify its students. Children slip through the cracks and illegal aliens are enrolled all the time. And this is a small bureaucracy. Where you should be able to get to a person that knows if some unknown child is in their class. But, it cannot verify that a child does not belong there. After a handful of teachers, it gets too complicated to make sure you ask all teachers if this kid belongs.

So, just considering a small set of our problem, we find that none of these ways actually works. Children that have moved, are still enrolled. The same child is enrolled somewhere else. Children that aren't supposed to be there are enrolled. Keeping more children on the books is a boon for finance.

And then there is the problem children. The ones that get probation all the time. Are they out or in? Are they missing because they are dead, or because they are in JV? These kids usually don't want to be there anyway, so it is not in their mood to help keeping their papers straight.

Add to that people being born and raised out in the Okees, people showing up and disappearing all the time. And what will you do with walk ins?