The best way to look at education is not as a private or public good, but from the perspective of reality: All people are different, and diverse people cannot be equally served by a single school system. Some parents want their children to learn that Columbus was good, some bad. Some kids are ready for algebra in eighth grade, some as sophomores. Some students respond well to zero-tolerance discipline, others don't.
Once you acknowledge reality, there's no question that a monolithic system will be hopelessly inefficient. Worse yet, it will foster incessant conflict as people try to get the schools to teach the things they — not somebody else — want.
The law in New Hampshire is one way of dealing with reality. It is an effort to allow parents or children who want or need something different to get it. It's a nearly immovable escape hatch — parents would have to pay to develop their preferred curricula, while schools could potentially face overwhelming demands to furnish personalized learning — but it at least acknowledges that one size does not fit all.
A far better option is to move to a system that functions naturally and smoothly with diversity — school choice. Let parents control education funding, and give educators freedom. Then numerous schools will spring up and parents will be able to pair with educators who share their views, or whose schools focus on the specific needs of nonuniform children.
But what about the public good? Aren't there some things that we agree every child must learn?
If we all agree, then freedom is no threat; parents will choose schools that teach those things. And if we don't?
Look no further than endless warring over evolution to see what happens when we ignore reality in service of the perceived public good. As Michael Berkman and Eric Plutzer recently documented, even when state standards call for the teaching of evolution, big percentages of high school biology teachers skip it. Why? To avoid conflict with objecting parents and students.
In other words, by trying to force evolution instruction on everyone, even those who want it often miss out. But that's what happens when you ignore basic reality.