>Per student funding in the private system is lower than per student funding in the public system. If you dump all of the special needs kids and the kids that

>Per student funding in the private system is lower than per student funding in the public system. If you dump all of the special needs kids and the kids that require a ton of effort to learn into a single group then OF COURSE these kids will be more expensive to teach per student than the most motivated students who can afford outside tutors etc. The whole premise of the article is that selection bias is a big deal.