Scott E. Carrell

From Natural Variation to Optimal Policy? The Importance of Endogenous Peer Group Formation

We take cohorts of entering freshmen at the United States Air Force Academy and assign half to peer groups designed to maximize the academic performance of the lowest ability students. Our assignment algorithm uses nonlinear peer effects estimates from the historical pre-treatment data, in which students were randomly assigned to peer groups. We find a negative and significant treatment effect for the students we intended to help. We provide evidence that within our �optimally� designed peer groups, students avoided the peers with whom we intended them to interact and instead formed more homogeneous subgroups. These results illustrate how policies that manipulate peer groups for a desired social outcome can be confounded by changes in the endogenous patterns of social interactions within the group.

Peer Effects in Academic Cheating

Using self-reported academic cheating from the classes of 1959 through 2002 at the three major United States military service academies (Air Force, Army, and Navy), we measure how peer cheating influences individual cheating behavior. We find higher levels of peer cheating result in a substantially increased probability that an individual will cheat. One additional college student who cheated in high school drives approximately 0.33 to 0.47 additional college students to cheat. One additional college cheater drives approximately 0.61 to 0.75 additional college students to cheat. These results imply, in equilibrium, the social multiplier for academic cheating is approximately three.

In Harm's Way? Payday Loan Access and Military Personnel Performance

Does borrowing at 400% APR do more harm than good? The U.S. Department of Defense thinks so and successfully lobbied for a 36% APR cap on loans to servicemen. But existing evidence on how access to high-interest debt affects borrowers is inconclusive. We estimate effects of payday loan access on enlisted personnel using exogenous variation in Air Force rules assigning personnel to bases across the United States, and within-state variation in lending laws over time. Airmen job performance and retention declines with payday loan access, and severely poor readiness increases. These effects are strongest among relatively inexperienced and financially unsophisticated airmen.

Does drinking impair college performance? Evidence from a regression discontinuity approach

This paper examines the effect of alcohol consumption on student achievement. To do so, we exploit the discontinuity in drinking at age 21 at a college in which the minimum legal drinking age is strictly enforced. We find that drinking causes significant reductions in academic performance, particularly for the highest-performing students. This suggests that the negative consequences of alcohol consumption extend beyond the narrow segment of the population at risk of more severe, low-frequency, outcomes.

Do Lower Student to Counselor Ratios Reduce School Disciplinary Problems

Abstract The American School Counselor Association (ASCA) recommends that there be no more than 250 students to each school counselor. Although numerous studies in the education literature show that school counselors play a positive role in educating children, to our knowledge, this is the first study answering the question of whether lower student to counselor ratios, all else equal, improve student outcomes. Using data provided to us by Floridas Alachua County School District and the University of Florida Counselor Education Department, we show that lower student to counselor ratios decrease both the recurrence of student disciplinary problems and the share of students involved in a disciplinary incident. These effects are greater for minority and low-income students. The fixed-effect models used, control for all unobserved heterogeneity across schools, isolating the effects on discipline from the within-school changes in the student-to-counselor ratio. The empirical methodologies employed produce unbiased estimates as long as the variation in the student to counselor ratio is not driven by unobserved factors that affect disciplinary outcomes.

Family Business or Social Problem? The Cost of Unreported Domestic Violence

Social interest in problems such as domestic violence is typically motivated by concerns regarding equity, rather than efficiency. However, we document that reporting domestic violence yields substantial benefits to external parties. Specifically, we find that while children exposed to as-yet-unreported domestic violence reduce the achievement of their classroom peers, these costs disappear completely once the parent reports the violence to the court. This suggests the public has an interest in helping families overcome their problems in general, and to report domestic violence in particular. It also suggests that social and judicial interventions may help combat negative peer effects in schools.

Are School Counselors a Cost-Effective Education Input?

While much is known about the effects of class size and teacher quality on achievement, there is little evidence on whether policymakers can improve education by utilizing non-instructional resources. We exploit plausibly exogenous within-school variation in counselors and find that one additional counselor increases boys’ reading and math achievement by over one percentile point, and reduces misbehavior of both boys and girls. Estimates imply the marginal counselor has the same impact on overall achievement as increasing the quality of every teacher in the school by nearly one-third of a standard deviation, and is twice as effective as reducing class size by hiring an additional teacher.