TQB: Teacher Quality Bulletin

Ripple effects: effective teaching echoes for years

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The nation has taken steps toward giving all students, regardless of their background, equal access to great teachers. States have been tasked with creating plans to achieve this goal as part of ESSA (read our analysis of their educator equity plans here). An important question remains: By more equitably distributing teachers, can schools actually get more equitable results, or are teachers too small a piece of the achievement puzzle?

New research from Dan Goldhaber, Roddy Theobold (of AIR and CALDER), and Danielle Fumia (of Washington State Institute for Public Policy) says "yes," equitable distribution of teachers will have a big impact. If schools were to equitably assign equally effective teachers to all students in fourth through eighth grades, they could significantly narrow the achievement gaps for low-income and underrepresented minority students, as measured by eighth grade math test scores and students' choice of math courses in high school.

Previous work has established that teacher talent is not evenly distributed. This study goes a step further, drawing a line between persistent inequities in teacher quality and students' future academic outcomes. In essence, this study measures how a more equitable distribution of teachers could shrink achievement gaps several years down the road.

Using 11 years of student data to estimate what would happen if all students have theoretical equal access to teacher talent in grades four through eight, they find that the gap in eighth grade math scores for underrepresented minority students would shrink by 16 percent. Similarly, if schools equitably assigned teachers to students who are eligible for free and reduced price lunch and those who are not, the gap in their eighth grade math scores would drop by 21 percent. A more equitable distribution of teachers could also significantly increase the likelihood that low-income students and students of color will take advanced math courses in high school.

These changes are meaningful, but are dwarfed by what could happen if students left third grade with the same level of achievement regardless of race or economics (an accomplishment no doubt requiring a more intensive intervention than systematically assigning similarly capable teachers). If this were the case, the eighth grade achievement gap would shrink by roughly two thirds.

Like research on the risks of strategically switching teachers between grades, this finding suggests that placing the strongest teachers in early grades may actually yield a bigger benefit to children than placing these great teachers in later, tested grades.

Of course, equitably assigning teachers would reduce achievement gaps, but not wipe them out. This work is a timely reminder of the value in assigning our strongest teachers to the students who need them most - and in placing a premium on effective instruction in early grades, even if these grades slip under the radar of some standardized tests.