Disruption in the classroom: experimental evidence from Ecuador

We study how poorly-behaved children affect learning and other outcomes of their peers using data from a unique experiment in Ecuador. Within each school, students were randomly assigned to classrooms in every grade for seven consecutive grades, between kindergarten and 6th grade. Children with persistent behavioral problems lower the math and language achievement of their classmates. The more poorly-behaved children there are in a classroom, the larger is their negative impact on the achievement of their classmates. These negative impacts are larger for younger children, and they persist for at least two years after exposure to a poorly-behaved peer. There are no dynamic complementarities in the impact of poorly-behaved peers: impacts are similar for children who were and were not previously exposed to poorly-behaved peers (and for high and low ability children). We find indirect evidence that children with persistent behavioral difficulties are passed around schools.