Ubiquity

Recent scholarship suggests that good teachers, even kindergarten teachers, increase their students’ earnings many years later. Eric A. Hanushek of Stanford University found that an excellent teacher (one a standard deviation better than average, or better than 84 percent of teachers) raises each student’s lifetime earnings by $20,000. If there are 20 students in the class, that is an extra $400,000 generated, compared with a teacher who is merely average.