I think the biggest problem, at least in the inner city schools is that a large portion of the funding comes from property taxes. Surprisingly enough, in poor areas, they don't get much property tax (because poor people don't own property). What happens is pretty predictable -- the inner city schools are incapable of educating the kids. They have 10 books for 4 classes of 30 each.
You cannot teach that way, not even if you're the best fucking teacher on the planet. PS, you don't make much more than you would if you'd not even gone to college and had instead worked your way up to managing a Wal-Greens. You can't attract anyone of reasonable skill if they could make more money and have to put up with less bullshit elsewhere. So spare me this "Union" crap. I'll believe that teachers are "overpaid" when I stop hearing about suburban teachers needing foodstamps.