Public schools: Teachers tend to be credentialed (or have a MA in education). They tend to have completed "student teaching" hours. They tend to have union protection, and this makes those who are successful (even moderately successful) more likely to complete their careers as teachers.
I actually see many of these attributes as negatives, especially the one about having degrees in education. From what I've seen of course offerings and requirements, it's a fluffy subject. Plus, education majors tend to have low SAT, GRE, and Miller Analogies scores. Obviously, there are some education majors who have high scores on these tests, but they're not the rule. Personally, I'd prefer to see subject experts teaching, even at the elementary level.
And having union protection can
also encourage mediocre teachers to stay where they are.
IMO, part of our problem in this country is that we lack a serious national interest in educating our kids and young adults (too many administrators, stratospheric college costs, and student loan debt being a good illustration of what I mean here).
