Thoughts on the economics of public education

There is an interesting  article in The Economist, based on "Measuring the Impacts of Teachers II: Teacher Value-Added and Student Outcomes in Adulthood" by Raj Chetty, John N. Friedman, and Jonah E. Rockoff. It notes:

The authors reckon that swapping a teacher at the bottom of the value-added spectrum with one of average quality raises the collective lifetime income of each class they teach by $1.4m. That rise would apply across all the teacher’s classes and over the whole of his or her career.

That suggests that we could invest quite a bit in improving the quality of teachers. I suppose that could be done by better training of aspiring teachers, better selection of teachers, more and better support for teacher improvement while they are in service, performance incentives for good teaching, and firing teachers who are performing nor improving.

The article also states:

Across schools, however, better pupils are assigned to slightly better teachers on average. The common practice of “tracking” pupils (filtering good ones into more advanced courses) could be to blame, the authors reckon, though they abstain from drawing firm conclusions. Whatever the cause, getting more effective teachers to instruct better-performing pupils naturally exacerbates the gap in achievement. Making the best teachers work with the worst pupils could go a long way toward minimising the yawning differences in attainment within a school system, the authors contend.

 Clearly there is value in increasing equity in schooling. Condemning kids who score low in their early exams should not condemn them to a decade of poor teachers. On the other hand, there may be value in giving the best students the best teachers. The value to society is not just the potential earnings of the students. It includes "externalities" such as the contributions that they make to the economy that are not captured in their remuneration. The medical scientists who are finding ways to prevent and cure diseases may not be earning as much as the people who run Wall Street firms, but they may do more good. It may be that giving the kid who has the potential to define a cure for cancer or Alxheimer's the best possible education is the best way to allocate teachers in his/her schools.