Stanford University’s Eric Hanushek puts the value of quality teaching in stark economic terms. Place even a slightly above-average teacher in front of a class of 20, and the resultant gain is more than $400,000 in future earnings over the earnings of students exposed to an average teacher. Replacing the bottom 5 to 8 percent of teachers with average instructors, he says, could lift the U.S. near the top of international math and science rankings.

Hanushek, the Paul and Jean Hanna Senior Fellow at Stanford’s Hoover Institution, discusses the economic value of effective teachers and the assertion that their impact is sufficiently large to make significant changes in how we evaluate and reward them.