Assuming that is true, did he say why it is true?
I can say from my own undergrad experience that education majors tend to go for that degree b/c it’s usually one of, if not the, easiest degree programs. My roommate’s girlfriend (now wife < shudder >) was a complete raging moron in every measurable and subjective way. She was an education major and graduated, no problem! She’s now teaching the next generation at the elementary/middle school level. Horrifying.
Her face is what always comes into my mind when I think about why we’re homeschooling our kids.
I certainly can't judge their motive but I can guess that these bottom-feeders cannot GET any other work except social work or as public school teachers, and at least teaching provides them with job security and union protection.
And I don't mean to insult teachers in general; my kids attend private elementary and high schools, and while our teachers are not perfect, the deadwood lasts nary a year. All of them serve on one-year contracts so firing is not necessary.
In fact, many of the teachers at my kids' school are retired from other walks of life. They make fabulous teachers because they definitely are not in it for the money or job protection.
As for Sowell's point, it's an old thesis of his and here are several links:
http://www.jewishworldreview.com/cols/sowell062000.asp"
http://econfaculty.gmu.edu/wew/articles/99/Time-for-Truth.htm