Ordinal Rank, Peer Composition, and Ability Tracking in University. Evidence from a Randomized Experiment

We use data from two experiments that randomly assign students to groups to show that, so long as ordinal rank has a causal effect on educational achievement, estimates of the effects of peer ability composition obtained from models that omit rank are downward biased. This finding holds both in the standard linear-in-means model as well as in models that allow for non-linear and heterogeneous peer effects, and contributes to explain why previous studies have detected only modest effects of peer ability on achievement. We also illustrate how this finding helps understand the mechanisms behind the effects of ability tracking policies.

Ordinal rank and the structure of ability peer effects

Purpose School and out-of-school social environments influence students’ learning process. This research paper aims to study school compositional effects by documenting the influence of students’ relative ranking within the school, in terms of their socioeconomic level and academic performance, on later educational outcomes. Design/methodology/approach To empirically assess these two influences, this study follows the universe of students attending the third grade in 2015–2016, until the sixth grade, in the Canary Islands. This study exploits changes in students’ relative position in terms of their academic performance and socioeconomic level during primary education. Two different approaches are used to measure students’ relative position: ordinal rank and distance to the average of the class. The identification strategy relies on student fixed effects to go beyond simple correlation. Findings The results show that being among the students with higher socioeconomic status in school is negatively associated with educational progression, which may be driven by peer effects. The opposite holds true for relative academic rank: being at the top of the school in reading and math positively influences absolute academic performance, which accounts for big-fish-little-pond effects. Additionally, heterogeneous peer effects are identified by school funding. Originality/value In light of the detrimental impact of social comparisons that often occur in school settings, teachers should actively promote student autonomy in setting personal goals and foster individualised growth, thereby mitigating the influence of social comparisons.

Understanding how student peers influence learning outcomes is crucial for effective education management in complex social systems. The complexities of peer selection and evolving peer relationships, however, pose challenges for identifying peer effects using static observational data. Here we use both null-model and regression approaches to examine peer effects using longitudinal data from 5,272 undergraduates, where roommate assignments are plausibly random upon enrollment and roommate relationships persist until graduation. Specifically, we construct a roommate null model by randomly shuffling students among dorm rooms and introduce an assimilation metric to quantify similarities in roommate academic performance. We find significantly larger assimilation in actual data than in the roommate null model, suggesting roommate peer effects, whereby roommates have more similar performance than expected by chance alone. Moreover, assimilation exhibits an overall increasing trend over time, suggesting that peer effects become stronger the longer roommates live together. Our regression analysis further reveals the moderating role of peer heterogeneity. In particular, when roommates perform similarly, the positive relationship between a student’s future performance and their roommates’ average prior performance is more pronounced, and their ordinal rank in the dorm room has an independent effect. Our findings contribute to understanding the role of college roommates in influencing student academic performance.

The Linear Threshold Model is a widely used model that describes how information diffuses through a social network. According to this model, an individual adopts an idea or product after the proportion of their neighbors who have adopted it reaches a certain threshold. Typical applications of the Linear Threshold Model assume that thresholds are either the same for all network nodes or randomly distributed, even though some people may be more susceptible to peer pressure than others. To address individual-level differences, we propose causal inference methods for estimating individual thresholds that can more accurately predict whether and when individuals will be affected by their peers. We introduce the concept of heterogeneous peer effects and develop a Structural Causal Model which corresponds to the Linear Threshold Model and supports heterogeneous peer effect identification and estimation. We develop two algorithms for individual threshold estimation, one based on causal trees and one based on causal meta-learners. Our experimental results on synthetic and real- world datasets show that our proposed models can better predict individual-level thresholds in the Linear Threshold Model and thus more precisely predict which nodes will get activated over time.

This paper investigates the causal effect of ordinal rank on students' academic performance in the short run. This paper provides the first direct evidence of the relationship between objective rank and students' self-perceived rank, as well as of the impact of the self-perceived rank on students' academic attainments. The results show that students' objective rank has a significant positive effect on students' test scores. Nonetheless, when self-perceived rank and the objectively measured rank are considered simultaneously, the self-perceived rank dominates the effect on the students' educational achievement, indicating that the objective rank largely functions as a proxy for the rank of which students are aware. Taking advantage of the very detailed survey questions aimed at students, parents, and teachers, a large set of potential mechanisms are examined in the paper.

Using data from international speed skating events in the 2012–13 through 2018–19 seasons, I investigate heterogeneous peer effects by gender, task, and monetary incentive. While I do not detect peer effects among men, I find evidence for such effects in some race distances among women. In the women's sprint races of 500 and 1000 meters, a 10% improvement in a peer's personal best prior to this event makes one's time faster by 0.30–0.38%, and a 10% improvement in a peer's time makes one's time faster by 0.93–1.02%. However, in 1000‐meter races for women, peer effects decrease sharply in events without monetary prizes. These results imply that monetary incentives are more effective than peer effects to improve one's performance in a middle‐ or long‐term task that requires patience. This article indicates that the effectiveness of peer effects depends on task characteristics and monetary incentives.

Using data on international speed skating events in the 2012/13–18/19 seasons, I investigate heterogeneous peer effects by gender, tasks, and monetary incentives. While peer effects do not work among men, I find evidence for peer effects in sprint races among women (500 and 1,000 meters). However, in 1,000-meter races for women, peer effects work only in events with monetary prizes. Interestingly, reducing the number of skaters who can earn prize money does not increase peer effects in 1,000-meter races among women. In hard tasks like 1,000-meter races, it may be important rather the presence than the competitiveness of monetary incentives.

In this paper, I present evidence of heterogeneous peer effects in the federal appellate courts. Prior work on judicial decision-making offers convincing evidence that federal appellate judges are influenced by both personal ideology and the ideologies of the judges with whom they sit to decide cases. It is likely that such peer effects are heterogeneous: that is, that peer influence is not uniform across all judges and all cases. This work uses a random sample of roughly 10,000 federal appellate opinion published over four decades to examine heterogeneity in peer effects across several dimensions. In particular, I find that peer effects are heterogeneous by workload (stronger in court-years with more caseload constraints), by previous experience (stronger among appellate judges with no prior judicial experience), by tenure (stronger among judges in the middle of their careers), and by case type (stronger in cases that are more ideologically-charged). The results paint an incomplete picture of the reasons for panel effects and suggest that many mechanisms might be at play.

This study estimates peer effects in diverse friendship networks by friend types. Evidence from friendship networks for 57,351 U.S. high school adolescents demonstrates that adolescents are more likely to make friends with someone of the same immigrant status or ethnicity (similar friends) than those with different backgrounds (dissimilar friends) and they interact more with their similar friends. Both types of friends influence adolescents' misbehaviors of smoking and drinking; yet similar friends have greater influences. Various potential mechanisms are contested, and the results suggest that higher interaction with similar friends can explain the heterogeneous peer effects.

ABSTRACTThis study estimates peer effects in diverse friendship networks by friend types. Evidence from friendship networks for 57,351 U.S. high school adolescents demonstrates that adolescents are more likely to make friends with someone of the same immigrant status or ethnicity (‘similar friends’) than those with different backgrounds (‘dissimilar friends’) and they interact more with their similar friends. Both types of friends influence adolescents' misbehaviors of smoking and drinking; yet similar friends have greater influences. Various potential mechanisms are contested, and the results suggest that higher interactions with similar friends can explain the heterogeneous peer effects.

Heterogeneous peer effects on marijuana use: Evidence from a natural experiment.

Heterogeneous peer effects and gender-based interventions for teenage obesity.

This paper uses matched survey and administrative data on first-year Economics students who were studying at the Javeriana University in Bogotá, Colombia, in 2015 in order to estimate peer effects on student grades. We employ the strategy proposed by De Giorgi, Pellizzari & Redaelli (2010) to identify and estimate these peer effects. Our results show that peer effects are economically significant in their context, that they result from the sharing of specific rather than general skills among peers, and that they flow mainly from peers with whom students interact frequently and who are considered to be leaders.

This paper explores the role of gender heterogeneity in the social diffusion of obesity among adolescents and its policy implications. We propose a generalized linear social interaction model which allows for gender-dependent heterogeneity in peer effects through the channel of social synergy. We estimate the model using data on adolescent Body Mass Index and network-based interactions. Our results show that peer effects are gender-dependent, and male students are particularly responsive to the weight of their female friends. Our simulations indicate that female-tailored interventions are likely to be more effective than a gender-neutral approach to fight obesity in schools.