Throwing students at classrooms
New York City Mayor Michael Bloomberg said last week that if it were up to him, he’d double class size and fire the 50 percent of teachers who are in the bottom half of effectiveness ratings: “doubl[ing] the class size with a better teacher is a good deal for the students.” Bloomberg, in his inimitable way, breezily insulted 80,000 teachers to make a point unsubstantiated by any social-science evidence.
When I heard about the mayor’s remarks to students at MIT, I was reminded of a school finance court case in Maryland some 30 years ago for which I served as a consultant. (At the time, I was a young doctoral student.) The poorest districts in the stat