What fraction of teachers were undergraduate education majors? I’d assumed that the answer was most, but not all. The Baccalaureate and Beyond data lets us look at students who graduated college in 2007-2008 and who were preK-12 teachers in 2012.
Looks like just a bare majority of teachers were undergraduate ed majors. Nearly the same number majored in something other than education. Since these numbers are for relatively recent graduates, I wonder if the pattern holds more generally.