A Field Experiment on Workplace Competition and Labor Supply

Last registered on June 26, 2019


Trial Information

General Information

A Field Experiment on Workplace Competition and Labor Supply
Initial registration date
June 17, 2019

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
June 26, 2019, 1:59 PM EDT

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



Primary Investigator

Texas A&M University

Other Primary Investigator(s)

PI Affiliation
University of Zurich
PI Affiliation
University of Virginia

Additional Trial Information

Start date
End date
Secondary IDs
This study develops a novel field experiment to test the implicit prediction of tournament theory that competition increases work time and can therefore contribute to the long work hours required in elite occupations.
External Link(s)

Registration Citation

Miller, Amalia, Ragan Petrie and Carmit Segal. 2019. "A Field Experiment on Workplace Competition and Labor Supply." AEA RCT Registry. June 26. https://doi.org/10.1257/rct.4266
Former Citation
Miller, Amalia, Ragan Petrie and Carmit Segal. 2019. "A Field Experiment on Workplace Competition and Labor Supply." AEA RCT Registry. June 26. https://www.socialscienceregistry.org/trials/4266/history/48719
Experimental Details


Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Work time and effort, output and labor costs
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
A university professor sent emails to departmental undergraduate major email lists with a research assistance (RA) job announcement (for benchmarking and testing a computer program to be used in future research) that invited interested applicants to click on a link to an online survey to apply. The email made it clear that multiple RAs were needed and would be hired for the same position. Applicants had several days to complete the online survey, and the work sessions were held in conveniently located library study rooms on campus. Potential workers were provided a link to a secure website where they can apply for the position and provide contact (name, email address, phone number) and background (gender, major, year, GPA) information and list their periods of availability during the workweek.

Conditional on availability and gender, applicants were randomly assigned to one-hour work sessions (particular time slots on particular days) in such a way that each session had an equal number of men and women assigned to that session. Applicants were informed by email that they were hired, provided with the date and time of the work session and the location of a central room used for intake, and asked to confirm their employment by clicking a link and completing an online form.

In this email, they were explicitly told that they would be working in groups and asked to therefore arrive a few minutes early to ensure a timely start. To increase attendance at the work sessions, workers who confirmed employment were sent a reminder the day before the assigned session. Slots that opened up because invited workers declined the invitation were reassigned to other applicants to the extent possible. No applicant was ever assigned to more than one work session.

Workers arrived at the work location and checked in with the manager at the central intake room. Workers were allocated into rooms to maximize the number of 4-person, gender balanced rooms. Workers in all rooms tested the same computer game, but different room-session combinations were assigned to different compensation scheme treatments.

At the designated session start time, trained graduate student assistants escorted the workers in groups to their assigned rooms to start the work. Workers sat in front of tablets, and the assistant described the task. During this brief training session, workers were told they only needed to work for 10 minutes and then complete a survey about the program to be paid the $25 wage. The nature and purpose of the work, including the value to the employer of the work and of additional effort from workers, were also explained to them. Workers were asked to try as hard as they could and to stay for as long as they could, for a maximum of 40 minutes. The assistant answered any questions, made sure the game was loaded and working on each of the tablets, and left the room. The work was conducted unsupervised unless workers encountered problems. Workers were instructed to leave their tablets on the table when they departed. The last worker to leave each room was asked to send a text message to inform the manager that the room was empty so that the tablets could be secured. Workers were all told they would be paid within 2 days. After each day of sessions, total amounts owed to each worker were computed, and workers were paid as promised via PayPal.

The two main treatments are a $30 tournament (TP30) and fixed payment (FP).

TP30: All workers who provide at least 10 minutes of work and then complete a questionnaire about the work are paid $25 for their time. In addition, workers in this treatment compete for a Tournament Prize bonus of $30 paid to one winner from each group of four workers.

FP: In the Fixed Payment treatment, workers perform the same task under the same conditions as those in TP30, except that they are paid the same $25 regardless of how long they work beyond the mandatory 10 minutes. Like TP30 workers, FP workers are kindly asked to stay for as long as they can (up to 40 minutes) and to work as hard as they can, because it will benefit the employer, but no bonus payment is offered beyond the promised $25.

We also examined two auxiliary bonus schemes: a $15 tournament prize (TP15) and a piece rate (PR).

TP15: We test if a lower prize amount as effective as $30 using a $15 prize paid to the winner of each tournament.

PR: We use the PR treatment to test if outcomes differ with individual incentives, based on absolute instead of relative performance. We set the price per point to match the actual average amount paid in bonus per point under the TP30 tournament, which was 3⅓ cents per point.

In rooms with a bonus scheme, the scheme was described to workers at the end of training.
Experimental Design Details
Randomization Method
Computer generated random numbers were used to randomly select individuals from the pool of applicants, conditional on their gender and availability, to fill work session slots.
Randomization Unit
Individual job applicants. The treatment was assigned at the room level. All workers in the same room at the same time worked under the same payment scheme.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
15 gender-balanced rooms of 4 workers for each treatment.
Sample size: planned number of observations
240 workers (15 rooms *4 treatments *4 workers).
Sample size (or number of clusters) by treatment arms
In total, the sessions generated data for an analysis sample of 236 workers. This includes 15 gender-balanced 4-person sessions in FP, TP15 and TP30 and 14 sessions in PR. There are only 14 piece rate rooms because one of the 15 sessions included a worker who had previously been hired under a different e-mail address. We detected the issue only after the work sessions were complete and were therefore unable to add another session.
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
University of Virginia IRB
IRB Approval Date
IRB Approval Number


Post Trial Information

Study Withdrawal

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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