Teach for America, the nonprofit organization that places high-achieving college graduates in school districts in underserved areas of the country, hasn't lacked for evaluations over the years. As I explained back in April, the majority of evaluations have shown either that TFA teachers are as effective as their peers, or that they are even better than traditional teachers in some categories. A vocal minority resists this conclusion, but the best data we have suggests that TFA either does no harm or does active good.
The best evidence we had before today was a randomized evaluation conducted by Mathematica Policy Research between 2001 and 2003, which found that TFA teachers bested other teachers at teaching math — with gains for students equal to about a month of additional instruction — and were not significantly different from them on teaching reading.
A follow-up using the same data showed that that result held for students across the math score distribution, not just the average student. "These results suggest that allowing highly qualified teachers, who in the absence of TFA would not have taught in these disadvantaged neighborhoods, should have a positive influence not just on students at the top of the achievement distribution but across the entire math test score distribution," the authors concluded.