Does classroom poverty lower students’ academic achievement? In other words, does a high incidence of poverty among students in a given class adversely affect their performance?
A large body of research suggests that it does, and a lot of education policy follows from that finding. But that research has a significant flaw, according to Douglas Lee Lauen, associate professor of public policy at the University of North Carolina at Chapel Hill. It relies on a limited data set. With a more powerful array of data, he says, “large effects basically disappear.”
Kids do, in fact, perform worse in classes where more kids are poor. But it’s hard to tell by looking at data from a single point in time whether that’s because of a classroom effect or because of how poverty affects individual students. The best way to tease out the causes of low achievement would be through an experiment. But as Lauen notes, “you’re not going to design an experiment to put a bunch of poor kids in a class deliberately and then see what happens.”
Lauen overcame the limitations of earlier research by following a cohort of individual children over time. He started with a group of 100,000 third-graders who were enrolled in public schools in North Carolina. Every year until they reached eighth grade, he tracked whether each child entered a poorer or richer classroom, and whether the child’s reading and math test scores went up or down. The design of this research helps clarify the relationship between those factors. If children consistently do worse in years when they are in poorer classrooms, then it would seem safe to say that classroom poverty is what causes the decline. Surprisingly, however, that isn’t what happens: Classroom poverty has no appreciable effect on test scores. “It’s not what I expected to find,” says Lauen.
“One explanation for this is that by the time a kid is eight years old, the effects of context have already been baked into the test score,” he says. “By third grade, it may be too late.” Another explanation is that the quality of a student’s teacher matters more than the background of his or her classmates.
Lauen conducted this research to show that school integration by socio-economic status can boost student achievement—but these results changed his mind. “Poverty mix within a classroom is probably not the most important factor,” he says. “A lot of political energy can be wasted on making assignment decisions to schools based on poverty level. That energy could perhaps more usefully be spent on improving teaching and learning.”
Other scholars disagree. More than 50 districts have implemented some form of socio-economic integration, and Lauen’s research doesn’t faze researchers who favor that approach. “What his paper rules out is the idea that just sitting next to a poor kid in your classroom makes your test score go down in that particular year,” says Sean Reardon, professor of education at Stanford University. “But that’s not the only way we think poverty might matter.” The differences between schools may be more important than the differences between classrooms, Reardon argues. It might be harder, for example, to attract good teachers to high-poverty schools. When socio-economic integration occurs, moreover, it takes place between schools—not between classrooms. Lauen “may be missing where all the action is,” says Reardon.