It's not about percentage of GDP used on education, it's about how socioeconomic status so strongly correlates with the quality of learning.

Reading comprehension, I've not only cited GDP, but also per pupil spending. We spend a ridiculous amount of money educating our middle class kids and get less than an acceptable results. Given the amount of money we spend on them our middle class kids should the absolute best.

Rich kids, kids with stay-at-home parents, who live in affluence, they tend to score higher on tests, have better grades, and get better educations.

They do because their parents are in essence homeschooling them! For the most part these parents are using schools for babysitting services, and doing the bulk of their education at home. In the US, every good parent homeschools, whether they are checking their kids homework, taking them to music classes, or dropping them off at the nearest Kumon Center.

You keep talking about poverty skewing the curve downward, but in reality "homeschoolers" are skewing the curve upwards. Both my wife an I got excellent educations abroad, we don't remember our parents having to be very hands on regarding our education. There were no extracurricular activities to ferry us to and from. We just went to school and the "experts" took care of the rest.

I said that educational experts specialize in classroom settings with a large number of students. Since I am teaching two students, individually, at home, I feel I can do that better than the alternative classroom experience.

You did, as a reply to my "DIY educators can run circles around so-called experts should be evidence enough that something is wrong with our educational system." Parents don't care about an individual's ability to "teach" to a group, they care about an individual's ability to teach to their child. A teacher is someone who can expertly impart knowledge and culture to an individual not someone who can expertly manage a crown. Besides there are plenty of homeschooling co-ops where parents take turns teaching each other's children (I belong to one), and they do a much better job than the so-called experts.