I looked for some data on the subject of teacher abilities. I found this:
In their hiring of teachers, do the nation's public schools get what they pay for?
By Virginia Postrel
The New York Times
March 25, 2004
...The best female students -- those whose test scores put them in the top 10 percent of their high school classes -- are much less likely to become teachers today.
''Whereas close to 20 percent of females in the top decile in 1964 chose teaching as a profession,'' making it their top choice, the economists write, ''only 3.7 percent of top decile females were teaching in 1992,'' making teachers about as common as lawyers in this group.
So the chances of getting a really smart teacher have gone down substantially. In 1964, more than one out of five young female teachers came from the top 10 percent of their high school classes. By 2000, that number had dropped to just over one in 10.
SAT scores of teacher wannabes
Sept. 2, 2008
High school graduates who say they intend to major in education score in the bottom third compared to 36 other intended majors, according to the SAT data released last week. Nationally, intended education majors finished 25th in reading, 27th in math and a combined 57 points below the national average in both...Students often change majors, of course. But is it a stretch to suggest the SAT scores are another sign the best and brightest don't want to teach?...
There was a rise in SAT scores of prospective teachers recently, but that's not saying much. Basically, teacher test scores are not as bad as they had been in recent years.
New York Times
Report Finds Better Scores in New Crop of Teachers
Dec. 12, 2007
"Teaching is attracting better-qualified people than it did just a few years ago, according to a report released Tuesday by the Educational Testing Service...
The SAT scores of prospective teachers who took the licensing tests in elementary education and physical education, however, were significantly below the average for all college graduates, it said..."
Selectivity - revisited
Posted November 5th, 2008 by Dave Saba
Joanne Jacobs has a great post pointing the way to Carpe Diem. It turns out that Education PhD’s have the second lowest GRE scores compared to any other academic focus. SAT scores are the same – in 2006, the College Board reported that only 2 majors had lower SAT scores than teachers – public relations and family studies.