I think there is some misunderstanding of which school is best for which student. Way back in the day, I met a person researching the issue and he explained that things were the reverse of what people typically think. The top students do best in public schools, Middlesome students do best in private schools. Special needs students tend to do better in public schools as well.
The reason for this has to do with the source of the income. Public schools are publically funded, which means that the teachers get to choose where to allocate their time and attention. Teachers tend to take to the extremes. Those teachers who love their subject will choose favorites from the bright motivated students in the class interested in the subject.
Those teachers motivated by charitable desires divert attention toward the special needs students. In many schools, average Joe student sits there and languishes. Students who are a bit rowdy are diagnosed with ADHD, given some pills to pop so that they will languish without disturbing the teacher.
The funding for private school comes from the parent's pocket. With parents as the customer, it is much more difficult to divert resources from student A to student B. The customer is much more attentive to any favoratism.
If your kid is super motivated and skilled at taking advantage of the resources offered, then they should go to public schools. The public schools have the deep pocket of the taxpayet to provide better quality resources. As I understand, more doctors and lawyers come from public schools.
If your kid has a hard time being motivated, they are better served by the private school that is trying to deliver a given product.
Special needs kids generally do better in public schools. Again, it is the matter that the public school is able to divert resources from the middle to administer the needs of the ends. Private schools are not in a position to divert resources from other kids to handle the special needs kids.
They do okay when the extra cost of handling special needs kids is figured in the price.
In a public school, the money comes from the government and it up to the students and teachers in a political process to decide how it gets spent. It is not uncommon to see $8k being allocated per student with some kids getting a $20k education and those in the middle getting short changed with a $3k education.
The private school, might get $5k per student, but it is not able to divert those resources either up or down. The middle students get short changed some, but not to the extent that would happen in a public school.
The student that is best served by the public school is your typical unmotivated teen from a middle or lower income family. Well educated parents who know how to use the system are better off sending their kids to the public school, then switching to private only if they have problems with the school.
The contrast of this article was written in broad strokes. Private schools tend to follow a business plan where they write a business model and design the education as product. A private school designed for special needs kids will rock. One just trying to give an education will have a hard time with the special needs kids. A private school dedicated to teaching the next generation of doctors will produce doctors. However, your run of the mill private school simply won't have the resources of a big public school.
In my ideal education system, I would want students to be able to get the resources that best suit their needs. That means a diverse education system with schools of different payment structures and interests. If a student isn't finding what they need at their current school, they should be able to move on.
The public schools, like other leftwing controlled institutions, have the nasty habit of playing the ends against the middle.
My ideal system is one where the schools design the product, and the students seek out the product that will help them develop and achieve positive goals.
Added 10/30/2007: Chicago University Report says Catholic Schools work in inner cities.