Finally, I am not clear what we should think the problem of American education (below the college level) is. Most children of middle-class (say upper quartile of households, income starting at $80,000) Americans are white or Asian and attend good public or private schools, usually predominantly white. The average white IQ is of course 100 and the Asian (like the Jewish) almost one standard deviation higher, that is, 115. The average black IQ is 85, a full standard deviation below the white average, and the average Hispanic IQ has been estimated recently at 89. Black children in particular often come from disordered households, which has a negative effect on ability to learn and perhaps indeed on IQ (which is only partly hereditary) as well. Increasingly, black and Hispanic students find themselves in schools with few white or Asian students. The challenge to American education is to provide a useful education to the large number of Americans who are unlikely to benefit from a college education or from high school courses aimed at preparing students for college. The need is for a different curriculum and for a greater investment in these children’s preschool environment. We should recognize that we have different populations with different schooling needs and that curricula and teaching methods should be revised accordingly. This recognition and response should precede tinkering with compensations systems. [Emphasis added.]
As someone who has been in both home school and public school, my experience tells me that the quality of education in home school is considerably higher than in public school. The main difference between the two is that in home school, my teacher was not only extremely invested in my educational future, but was also able to invest a significant amount of time teaching me one-on-one. This is not to suggest that my public school teachers were uncaring robots; on the contrary, most of my teachers took a personal interest in me and my educational development. Some of them even gave some of their personal time to better explain various concepts to me when I had trouble getting them the first time around. The difference, though, is this: as much as my public school teachers cared, and as much time as they gave me, they never did care as much as my mom nor could they give me as much of their time.
I think the chief failing of the public education system is that of scalability. To put it simply, centralization quickly runs into diminishing marginal returns. The reason for this is what Posner noted: there is simply too much human variability in existence to allow for a one-size-fits-all approach to education. What works for one student may not work for another. What works for one teacher may not work for another. Human beings are complexly unique, and treating them all alike, as if they are interchangeable, is an incredible mistake because it is not a reality-based approach. Once you accept that humans are unique, and that there is a high degree of variability in children’s learning process, it should become clear that a single, universal approach to education is bound to fail.
One reason, then, why home-schooled students are often intellectually and academically superior to their public-school peers is because the parents of home-schooled children implicitly recognize scalability in education is not a feature but a bug. Those who homeschool their children are able to provide them with a highly personalized education, which is quite an advantage academically. Those in public school have no such luck, and thus suffer academically because the economies of scale afforded by mass education do not actually extend to academics, but rather to costs.
Quite simply, education is not all that scalable, which is why it becomes progressively worse when centralized, particularly in areas of cultural and ethnic diversity. The best option for education would be homeschooling, and the second best is whatever has the smallest scale.