Social Econ Blog

This paper uses a unique data set to measure peer effects among college roommates. Freshman year roommates and dormmates are randomly assigned at Dartmouth College. I find that peers have an impact on grade point average and on decisions to join social groups such as fraternities. Residential peer effects are markedly absent in other major life decisions such as choice of college major. Peer effects in GPA occur at the individual room level whereas peer effects in fraternity membership occur both at the room level and the entire dorm level. Overall, the data provide strong evidence for the existence of peer effects in student outcomes.

This paper examines a natural experiment in which students at a large state university are randomly assigned roommates through a lottery system. We find that on average, males assigned to roommates who reported drinking in the year prior to entering college had one quarter-point lower GPA than those assigned to non-drinking roommates. The 10th percentile of their college GPA is half a point lower than among males assigned non-drinking roommates. For males who themselves drank frequently prior to college, assignment to a roommate who drank frequently prior to college reduces GPA by almost a full point. Since students who drink frequently are particularly influenced by frequent-drinking roommates, substance-free housing programs could potentially lower average GPA by segregating drinkers. The effect of initial assignment to a drinking roommate persists and possibly even grows over time. In contrast, students' college GPA is not influenced by roommates' high school grades, admission test scores, or family background. Females' GPAs are not affected by roommates' drinking prior to college. Overall, these findings are more consistent with models in which peers change preferences than models in which they change endowments.

Mixing across ethnic and class lines could potentially either spur understanding or inflame tensions between groups. We find that white students at a large state university who were randomly assigned African-American roommates in their first year are more likely to endorse affirmative action policies several years later. Whites who were randomly assigned black roommates are also more likely to say they have more personal contact with and interact more comfortably with members of minority groups. Whites who were assigned either black or low-income roommates are more likely to view a diverse student body as essential for a high-quality education. Students become less supportive of higher taxes for the wealthy when assigned roommates from high-income families, and they appear more likely to volunteer when assigned roommates from low-income families. Taken together, these results suggest that students become more empathetic with the social groups to which their roommates belong.

// posted by BW @ 5:44 PM