Not only can legislation impose excessive regulations on education providers, it can also open the door to costly litigation when rights and responsibilities are poorly defined. For example, when it enacted the Education for Individual with Disabilities Act, Congress never sufficiently defined the term "appropriate" in "free appropriate public education." In practice, that ambiguity has opened the door to costly litigation over what public schools are obligated to provide to students with disabilities.

That private schools serve such a variety of special-needs students, and sometimes enroll the most difficult among them, lays bare the myth of the public-school dumping ground and the notion that school choice will leave only the worst students in the public schools.

Says Devereux’s Thomas McCool:

We probably have at any given time, one or two children who are here privately. But then what the family does is once the child is here, they go back to the district and say this is the program I want. If you can duplicate that, and its got to have this kind of staff ratio, these kinds of activities, this kind of individualization, this kind of social-work support, this kind of clinical support . . . and they can’t do it. So a lot of [parents] go through the back door to get public funding.128