The Times and a host of other publications heralded last week's new study extolling the lifelong money-earning benefits of having a good primary/middle-school teacher. Oh, yay! Let's do what these economists from the National Bureau of Economic Research suggest, right?
Actually, ugh, no. What economists Raj Chetty and John N. Friedman of Harvard and Jonah Rockoff of Columbia want to do, apparently, is to identify and fire "weaker" teachers, for the sake of a barely perceptible increase in students' "lifetime income." Nobody has actually tried this yet; the report doesn't describe an experiment. It's just the conclusion they draw from their analysis of massive amounts [...]