Please fill out this short user survey of only 3 questions in order to help us improve the site. We appreciate your feedback!
Peer Effects in University
Last registered on September 06, 2018


Trial Information
General Information
Peer Effects in University
Initial registration date
September 06, 2018
Last updated
September 06, 2018 5:15 PM EDT
Primary Investigator
University of Zurich
Other Primary Investigator(s)
PI Affiliation
University of Zurich
PI Affiliation
University of Zurich
Additional Trial Information
In development
Start date
End date
Secondary IDs
In this project, we will randomly assign first-year university students to study groups of four students. We will conduct a baseline survey to measure student background characteristics, personality, and economic and social preferences. We will analyze how study groups should be composed in order to create social interaction and maximize learning spillovers. We will investigate which peer characteristics affect students’ performance and educational decisions.
External Link(s)
Registration Citation
Shan, Xiaoyue, Giuseppe Sorrenti and Ulf Zölitz. 2018. "Peer Effects in University." AEA RCT Registry. September 06. https://doi.org/10.1257/rct.3255-1.0.
Former Citation
Shan, Xiaoyue et al. 2018. "Peer Effects in University." AEA RCT Registry. September 06. http://www.socialscienceregistry.org/trials/3255/history/33941.
Experimental Details
Intervention Start Date
Intervention End Date
Primary Outcomes
Primary Outcomes (end points)
1. Exam grade, course passing, and course drop out in the introductory Microeconomics course
2. Exam grade, course passing, and course drop out in the other courses students attended in parallel
3. Subsequent grades (in particular in Microeconomics II)
4. Successful completion of the first study year
5. Students’ course choices
Primary Outcomes (explanation)
All data on primary outcomes come from administrative university data.
Secondary Outcomes
Secondary Outcomes (end points)
1. The number of times students met with their study group
2. The number of text messages written in their WhatsApp study groups
3. The number of tutorial meetings attended
4. Students’ perceptions of their group interaction and functioning
5. Students’ self-reported study hours and study intensity
6. Students’ role in their study group (explaining, listening, entertaining)
7. Students’ study group networks
8. Whether students are in a romantic relationship with a person from their study group
Secondary Outcomes (explanation)
Secondary outcomes are derived from administrative and end line survey data.
Experimental Design
Experimental Design
We will randomly assign first-year university students to small study groups.
Experimental Design Details
In September 2019 we will conduct a baseline survey among all students who registered for the introductory Microeconomics course. This baseline survey will collect pre-intervention information on student personality, attitudes, and social and economic preferences. After the baseline survey is completed, we will contact students and offer them the opportunity to sign up for study groups. All the students who agree to take part will be part of a four-student study group. Within these groups, students will exchange information, solve problem sets, and prepare for the exam. At the end of the intervention, we will collect administrative data about students' performance in the introductory Microeconomics course and in all the other courses they were enrolled in during the same semester. We will also conduct an end line survey measuring student attendance, peer-to-peer interaction, study habits, social networks and personality. After the experiment ends, we will follow students’ study careers and collect information about their subsequent performance and educational choices.
Randomization Method
The randomization will be done by the principal investigators in their office using the computer program STATA.
Randomization Unit
Randomization will take place at the individual level. Assignment to groups will be clustered by students’ study program. This implies that students will be randomly assigned to groups with peers from the same program.
Was the treatment clustered?
Experiment Characteristics
Sample size: planned number of clusters
Depending on the actual sign-up rates, we expect to observe 125-250 study groups of four students each.
Sample size: planned number of observations
500-1000 students.
Sample size (or number of clusters) by treatment arms
500-1000 students.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Based on the simulations we ran, we should we able to rule out effects larger than 3–6 percent of a standard deviation in grades. The precision of our estimates will depend on: 1) the number of students that sign up for the offered study groups, and 2) the measurement error in the survey measures, which is difficult to predict.
IRB Name
University of Zurich
IRB Approval Date
IRB Approval Number
OEC # IRB 2018-021
Post Trial Information
Study Withdrawal
Is the intervention completed?
Is data collection complete?
Data Publication
Data Publication
Is public data available?
Program Files
Program Files
Reports, Papers & Other Materials
Relevant Paper(s)