Becker, I like the article, but I wonder about the implications of the correlation between teachers improving test scores and the large effects on subsequent earnings. You seem to imply that because these students earn more, the teachers who taught them ought to be better. This is without doubt at least partially true. But I think it could also be true that good grades serve as a signal where employers with imperfect information try to hire the students with the best grades (independently of how connected such grades are to expected job performance). If this is the case, then if everyone received higher test scores, it would just lead to signal inflation--not a general improvement in education. How much research is there on the correlation between student success in mastering state exams and general success on the job? Rick