For the past couple of weeks, I've presented evidence from the National Assessment of Educational Progress (NAEP) math exams and else where indicating that private schools do not outperform public schools. When all is said and done, the NAEP exams tell us, kids who are about to graduate from private school are achieving at about the same low level as public school kids.

This is a shocking result given what we've been led to expect. After all, private schools have more advantaged students. They have no collective bargaining and no union contracts. They can pick their students -- and expel them if they turn out to be troublemakers. They don't have to worry about government regulations or due process or dealing with handicapped students. Given the constraints that public schools work within -- and from which private schools are free -- why are the two sectors getting the same poor results?

Students learn because of the work they do. The fact that students in other industrialized countries know more than our kids means they work more. And the fact that students in private schools are achieving at about the same low level as public school students means they're doing about the same tiny amount of work. We should not be surprised at this. Most people work because they must. If Congress passed a law tomorrow saying that work was voluntary but that people would go on drawing the same pay and benefits whether they worked or not, the country would fall apart. But that's what we've said to our kids.

College-bound students from private as well as public schools know they'll be able to find a college that will accept them, no matter how poor their grades are or how little they know. All they'll need is a high school diploma and, usually, money. The one exception is students who hope to attend elite colleges; they have to work very hard indeed.

As for going to work from high school, all students know that employers don't ask to see high school transcripts and don't even offer decent jobs to high school graduates until they are twenty-four or so, if then. So a student who has worked hard at rigorous courses will be competing for the same poor job at the same low pay as a student who has filled his schedule with soft courses that he barely passed. These bad lessons are being learned by students in public and private schools alike.

What about parents? Why aren't they making sure their children apply themselves? That's easy. Whether their kids are in public or private schools, most parents won't be successful in pressuring them to work harder when the kids can say, "Why are you torturing me? I've already done what I have to in order to get what I want and you want for me."

One solution is for American businesses to link getting jobs to high school achievement and for colleges to do the same thing in setting admission standards. Elementary and secondary schools would then have support for upholding standards. Parents would have support when they said, "Unless you work harder, you're not going to make it." And our students would see a reason to achieve -- and they would.

But incentives for students will not do the job alone. We also need a system of incentives to stimulate improvement in the schools. Supporters usually present private-school choice as such a system, with the incentive for public schools being, Shape up or lose your customers to private schools." But given the poor results in private as well as public schools, it's hard to see how getting the two sectors to compete will improve the education our students are getting. Besides, there's no evidence that schools would be chosen on the basis of educational excellence. From what we already know about choice, a good location or a day care program or top-notch sports facilities are more likely to dictate the choice of a school than a first-class academic program.

So choice may be a terrific incentive for getting schools to work at attracting customers, but it's a dubious one for getting schools to focus on improving student achievement. The only way to do that is to design incentives that would reward the entire staff of a school for success in consistently improving student achievement and single out or even punish the staff of a school where students consistently fail to improve. This is a radical idea and a controversial one. We would need to test it to see what incentives work and when and how. But the idea of basing school accountability on private school choice is also radical and controversial, and NAEP and other results tell us it is unlikely to work.

The President's private school choice program is cheap in every way; it doesn't cost any money or any pain. There are solutions for the problems that face our schools -- just as there are solutions for the health care crisis and the budget crisis -- but pursuing any of them will cost us something, and the President prefers a program that requires no sacrifice. We know, however, that in education, as in these other areas, gimmicks and slogans will not solve our problems. We won't have improvement in education until kids know, and school staffs know. That there are consequences for success and failure -- until we accept the fact that there will be no gain without pain.