McGrath is a college professor. He should know better than to fall for shitty statistics. The study he cites used a volunteer sample of students from highly motivated highly educated non-poor families. To match the effect of homeschooling you need to compare these students with demographically matched peers, not the public school average. The results of studies that use from a more comprehensive data set (see the data covered here) or pair students with demographically matched peers (see Martin-Chang here) look far different from those released by Ray, whose National Home Education Research Institute is for all intents and purposes an arm of the Home School Legal Defense Association.
The lack of oversight for homeschooling in most states is a very serious problem, and leaves too many children without an education.
Тётенькин лучший аргумент - это она сама: училась дома, и вот пожалуйста.