Contract Enforcement and Investment: Evidence from a Field Experiment

Last registered on May 01, 2020


Trial Information

General Information

Contract Enforcement and Investment: Evidence from a Field Experiment
Initial registration date
April 29, 2020

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
May 01, 2020, 3:35 PM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.



Primary Investigator

McGill University

Other Primary Investigator(s)

Additional Trial Information

In development
Start date
End date
Secondary IDs
Contract enforcement institutions may increase investment. In this paper, I implement a field experiment where individuals in teams engaged in teamwork sign a team contract. The goal is to see whether signing a contract increases effort provided in teams.
External Link(s)

Registration Citation

Chemin, Matthieu. 2020. "Contract Enforcement and Investment: Evidence from a Field Experiment." AEA RCT Registry. May 01.
Experimental Details


The intervention consists in sending a contract to teams engaged in teamwork. Team output is graded and counts for 30 percent of the final grade in a real university course. The grade is the same for all students in the same team, which creates a free-riding issue: every student has the incentives to let others do the work and benefit from the team grade. In one third of the teams, students will write a team contract to set firm expectations from the beginning and will send the contract to the professor. In another third of the teams, students will write a contract and send it to a teaching assistant who has no authority to change the grades (to test whether the strength of enforcement matters). A final third of the teams will serve as a control group.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The primary outcome is free-riding, measured by effort on the teamwork, measured by:

• questions 10 (Indicate who contributed a fair share to the teamwork), 11 (Indicate who was on time to the team meetings), 12 (Indicate who respected the deadlines set by the group), 13 (Indicate who showed enthusiasm and a positive attitude in the team)

• questions 18,20,22,24 (What was the contribution of student X in the teamwork?) in the questionnaire

• questions 3 (How many times did your team meet to work ?), 4 (How many hours did you work on the teamwork this past week ?)

These outcomes will be looked at only if there is sufficient variation in the data.

I will use a difference-in-differences analysis. Multiple hypothesis testing will be with the Sharpened False Discovery Rate (FDR) adjusted q-values (Anderson, 2008).

The research plan includes subgroup analyses by:

• number of friends before the teamwork (question 16: Who were you friends with before the teamwork?) since a contract might be less needed in teams with a greater proportion of friends.

• first or second teamwork in the course (contracts may not be necessary with repeated interactions)

• high- or low-ability teams (contracts may be less needed when the rest of the team is of high-ability, peer effects may substitute to contracts).
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
• Team performance: grade on the teamwork

• Academic performance: grades on quizzes and exam, as well as question 5 (How many hours did you work on the rest of the class (lectures, quiz…) this past week ?)

• Opinion about the teamwork (positive experience, stress, friendships after teamwork): questions 1 (Did you appreciate the teamwork assignment ?), 2 (Do you think the work done helped you develop your teamwork skills ?), 6 (Did your group appropriately split the tasks among team members ?), 7 (What kind of problems, if any, did you encounter in your team ?), 9 (Do you think that this work a. Allowed you to acquire new knowledge in development economics b. Allowed you to get familiarized with new methodologies c. Allowed you to increase your knowledge about the topic d. Was globally beneficial for you in your studies), 14 (Was there a leader in your team), 15 (Indicate the members who taught you something during teamwork), 17 (Who are you friends with now), 27 (How stressed were you by the teamwork?)

• Number of complaints to the professor (and to the TAs)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
• In one third of the teams selected randomly, students write and sign a team contract, which is sent to the professor for enforcement.

• In another third of the teams selected randomly, students write and sign a team contract, but only send it to a teaching assistant who has no authority to change the grades.

• Finally, in the last third of the teams, there will be no team contract.
Experimental Design Details
Randomization Method
The randomization will be done in office by a computer.
Randomization Unit
Teams of 4 students will be randomly formed. The randomization will be at the team level.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
The planned number of clusters is a minimum of 120 teams.
Sample size: planned number of observations
The planned number of observations is a minimum of 480 students.
Sample size (or number of clusters) by treatment arms
40 teams with team contract to the professor, 40 teams with team contract to the TA, 40 teams control.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
McGill University Research Ethics Board
IRB Approval Date
IRB Approval Number
REB File #: 79-0710


Post Trial Information

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials