The right incentives can motivate a student to do homework, an employee to hit a quota, and even a child to finish her vegetables. Incentives can also positively shape the teacher workforce, if the incentives are designed correctly. The million dollar question then becomes: are districts incentivizing the right stuff?

To delve into this issue, James Cowan (American Institutes for Research) and Dan Goldhaber (University of Washington-Bothell) studied an incentive program implemented in 2007 in Washington State. This program alloted $5000 bonuses to teachers who became National Board certified. To qualify for this bonus, National Board teachers had to agree to work in schools with a high proportion of students who are eligible for subsidized lunches. (Presumably the program was trying to resolve the problem that NBCTs are generally less likely to teach in high-poverty schools.)

Using these data, the researchers asked if financial incentives rewarding National Board certification lead to tangible improvement in high-needs schools.

As it turned out, the program did succeed in bringing more National Board teachers into high-poverty schools and in keeping them there. It also benefited the other teachers who were already working in these schools, motivating more to seek and gain Board certification. However, it fell short of its real purpose to drive improvement in student achievement in these schools.

The researchers theorize that the disappointing results were partially due to the fact that half of the National Board teachers in the schools had already been working there; going through the certification process does not make teachers more effective than they had been. Furthermore, while National Board certification does correlate with teacher effectiveness, the correlation is not particularly robust. The program just may not have been able to bring in enough new teachers capable of achieving measurable school-wide improvement.

Given that National Board certification is a relatively weak proxy for highly effective teaching, it's too bad that the incentive program didn't directly target highly effective teachers and get the great results seen in such places as Hamilton County, TN and Charlotte-Mecklenburg, NC.