National Board Certified teachers have to go to great lengths to prove their accomplishments. Quite a few states offer moderate bonuses to teachers who achieve NBCT status. So I’m a bit surprised at evidence offered by James Cowan and Dan Goldhaber that shows that getting board certified teachers into high-poverty schools doesn’t seem to do anything for student achievement.
Washington State has for some time offered bonuses, around $5,000, to board certified teachers. More recently Washington started paying an additional $5,000 to board certified teachers at high-poverty (as measured by free or reduced lunch enrollment) schools. Cowan and Goldhaber begin by checking whether the added bonus increased NBCT participation in schools. The answer is yes. More NBCTs were hired and more teachers in eligible schools applied for certification.
Looking at the authors’ picture you can see the jump up in eligible schools.
So the new bonus program did increase the number of certified teachers at eligible schools. It’s worth noting that there aren’t very many certified teachers around. So while the program increased the number of NBCTs at eligible schools by about a quarter, on average this is only about half a teacher per school.
Did the increase in board certified teachers lead to better student outcomes? Since there are relatively few NBCTs, you might expect a relatively modest improvement for the average student in an eligible school. Surprisingly, the evidence is somewhere between nothing happened and student achievement declined.
The authors’ student achievement picture:
Cowan and Goldhaber are quite careful with their statistical conclusion, pointing out that while the estimates are that more NBCTs led to a decline in student achievement that the estimates are imprecise. They can’t rule out small improvements in student achievement.
In sum, the evidence is weakly negative with regard to the impact of board certified teachers. Disappointing, and not what I would have expected.