A new Mathematica report looks at a randomized experiment in which high-performance teachers were paid to move to low-performance schools. Teachers ranked in the top fifth of teachers in their subject and grade were offered $20,000 to move to a school serving very disadvantaged students, conditional on remaining in that school for at least two years. The results of the experiment are being portrayed in the blogo-sphere as good news. There is some good news, but I think it’s exaggerated.
- The transferred teachers had a positive effect on elementary school test scores.
- The improvements were cost-effective, at least when compared to spending to decrease class size.
- After the end of incentive payments, transferred teachers were neither more nor less likely to bail out of their new school than anyone else.
Not quite such good news:
- In middle school, there weren’t any statistically significant improvements in student outcomes.
- Not many teachers were interested in moving for twenty grand. The program identified 1,514 candidates to fill 81 vacancies. And even with the incentive, the program was unable to fill 10 percent of its vacancies.
- No one measured whether students in “sending” schools lost out by having high-performing teachers leave.
Does it make sense to pay really good teachers to move to schools that need them badly, but that are tougher teaching assignments? Sure. But it’s going to take a lot more than one-time payments of $20,000 to get enough good teachers into all the classrooms that need them.