Examining Spillover Effects from Teach for America Corps Members in Miami-Dade County Public Schools
*Names in bold indicate Presenter
Using longitudinal data from M-DCPS spanning the 2008-09 through 2013-14 school years, we generate TFA impact estimates of effectiveness compared to similarly-experienced teachers within their same schools using student fixed effects. We estimate main TFA impacts of approximately 0.11 and 0.02 standard deviations of student learning gains in math and reading, respectively; estimates in both subjects are statistically significant. We then explore the relationship between the density of TFA corps members within schools and student achievement. Our findings suggest a significantly positive spillover effect in math onto non-TFA teachers associated with the dense clustering of TFA corps members. The spillover effect appears to be most significant in middle and high school grades, and is more closely related to the school-level density of TFA corps members (rather than grade- or subject-level densities of corps members). On balance, the results suggest a modest, though significant, effect on other teachers' performance from having large numbers of TFA in these targeted schools. We do not find any evidence that corps members’ performance was sensitive to any differences in clustering. Also, we do not find any evidence of a significant spillover effect in reading.
Finally, we observe that many of the schools chosen to participate in the cluster strategy experienced large subsequent gains in math achievement. Our results suggest these gains were driven primarily by the composition effect of having larger numbers of relatively effective TFA corps members staffing these schools. However, the evidence of a modest spillover effect appears to have contributed to the observed gains. In other words, the combined output of staffing dense clusters of TFA corps members is greater than the sum of the individuals' output in these district schools.