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.