[hackinthebochs]

I don't think you can dismiss money as incentive so easily. There is evidence that paying kids does in fact work (http://www.time.com/time/magazine/article/0,9171,1978758-1,0...). The point in starting the kids off as young as possible is that it will develop in them good habits. Not to mention the effect that an external incentive for kids in an entire region can have on the culture itself.

Poor black and hispanic kids are the same as everyone else in that they have no internal motivation to work hard at something unpleasant. The difference with white and asians is that they have the external incentive of a culture that supports working (reasonably) hard at school and becoming successful. Money is simply a hack to create this external incentive.