Experimental Design Details
Subjects are invited for sessions taking part at a specific time. Using a link provided in the invitation email, they enter a webpage. A page with basic instructions informs subjects that they take part in a scientific study, that they will interact with other subjects via an audio chat, and that the audio will be recorded for research purposes. Only subjects who give explicit consent to the recording and to the linking of the data generated during the experiment with administrative data from the university registry can participate. Subjects are then redirected to a microphone test. Next, subjects see a screen with instructions. We inform subjects that they will receive a show-up fee of EUR 10 and that they will work on a series of 10 single-choice problems in a team together with three other subjects they will meet in an audio chat room. We also inform them about a piece rate of EUR 1 for each correctly solved question, and that the piece rate will only be paid if all team members mark the correct statement. We add a statement that further money can be earned in a later stage. We then connect the team members via the chat room for stage 1. Teams have some time to say hello to each other. In the chat room, the subjects of a team are labelled from 1 to 4 (the order is randomly determined). Each team member's number is shown as an avatar in the audio chat and we visualize who is currently speaking. This enables subjects to directly address each other. Next, we instruct the subjects to familiarize themselves with further written technical instructions, including how to reconnect if the internet connection is lost. After that, the information material for the first block of problems is displayed, and teams start working on the problems. With 10 problems and 3 minutes to work on each problem in stage 1, teams work on the task for a total of 30 minutes (net of the time given for reading the information material).
Once the work on the task is completed, the chat room is closed and subjects answer survey 1 individually. The survey contains several items that elicit the subjects' perceptions of team communication and interaction (whether team communication was positive, whether it was cooperative, whether working jointly on task was enjoyable, plus items on quantity of communication, distribution of shares of speech, and interruptions), the belief about how many problems the team has answered correctly, and the belief about how much one has contributed to team output. We also ask subjects to indicate how many of the other subjects in their team they believe were female. In order not to reveal the purpose of the study, we also ask subjects how many of the other subjects in the team they believe are enrolled in certain fields of study, and how many they believe have completed at least two semesters at university.
At the beginning of stage 2, we inform subjects about a further stage of the study, and that they will earn an additional flat payment of EUR 2. We inform subjects that they will meet another subject in the chat room for one minute. Subjects are randomly assigned to form pairs of two. To form pairs, we randomly determine pairs of first-stage teams and randomly match subjects across teams. This makes sure that the newly formed pairs of two consist of subjects who have not met in stage 1. To make sure that subjects in a pair talk to each other, we display a random five-digit number on each subject's screen. Subjects are instructed to fill in the other subject's number in a field on their screen. Once the chat room is closed again, we inform subjects about the possibility that they will work on another task similar to the one in stage 1 for 15 minutes, and ask subjects to state their preference for working on the task individually or in a team with the subject they met in the chat room. The instructions also explain the random draw that determines which of the following scenarios will be implemented: (a) both subjects who met will work on the task individually, irrespective of their stated preferences; (b) their stated preferences will be implemented as follows: they work as a team if they both indicated this as their preferred option, and they both work individually otherwise; or (c) the subjects will not work on the task at all. The subjects then state their preferences for teamwork (binary choice between individual work or teamwork). The subjects' beliefs about their individual productivity is elicited as follows: we ask subjects to imagine they would work individually on a task similar to the one they have worked on in stage 1, but that the task would comprise 4 blocks of 5 problems each, giving a total of 20 problems. Given a piece rate of EUR 1 per correctly solved problem, we ask subjects to indicate how many problems they believe they would solve. Similarly, we ask subjects to indicate how many problems (out of 20) they believe the other subject would solve correctly when working on the task individually. Finally, we ask the subjects to state how many problems they believe they would solve when working with the other subject in a team under conditions as in stage 1. In addition, we elicit beliefs about team communication and interaction should the subject work with the potential teammate. For that purpose, we use similar items as in stage 1. Specifically, we use items measuring subjects' beliefs about whether the communications would be positive, whether it would be cooperative, and whether working jointly with the potential teammate on task would be enjoyable. Finally, survey 2 elicits the subjects' perception of the potential teammate's gender. In order not to reveal the purpose of the study, we also ask subjects if they believe the potential teammate is enrolled in certain fields of study and has completed at least two semesters at university.
The random draw regarding the subjects' actual work on the task will be parameterized such that (a) the probability for individual work irrespective of stated preferences is 5\%, (b) the probability for the stated preferences to be implemented is 5\%, and (c) the probability for no work on the task at all is 90\%.
The experiment ends with survey 3, eliciting the Big-5 personality traits. We use a 15-item survey to measure openness, conscientiousness, extraversion, agreeableness, and neuroticism.