Experimental Design
The structure of our experiment is as follows:
i) Subjects play a paintings game;
ii) Then, they play a coordination game with third-party negative externalities;
iii) Next, they play an allocation game;
iv) Finally, we measure their beliefs, their perceived social distance and collect some socio-demographic characteristics
1) Paintings game:
Subjects play the game either individually (Baseline) or in groups (Treatments 1 to 3).
If they play the game individually, they first have five minutes to individually analyze five pairs of paintings by Klee and Kandinsky, identified only as “Artist 1” and “Artist 2”. Then, they are given seven minutes to analyze a sixth pair of paintings and determine the artist behind each.
If they play the game in groups, subjects are randomly assigned to one of three groups: blue, orange, or green. First, they have five minutes to individually analyze five pairs of paintings by Klee and Kandinsky, identified only as “Artist 1” and “Artist 2”. Then, they are given seven minutes to analyze a sixth pair of paintings and determine the artist behind each. For the identification of the sixth pair, group members can communicate via an open chat, but not with members of other groups (e.g., green subjects can only communicate with green subjects, etc.). Each subject submits their choice individually, and correct answers are rewarded.
2) Coordination game:
A. Main structure of the game:
Subjects are randomly allocated in fixed groups of three (partner design): two C subjects and one Z subject. Roles remain fixed for the rest of the experiment and subjects do not know the exact identity of the other group members.
Subjects play a similar version of the coordination game proposed in Bland and Nikiforakis (2015) and Cason et al. (2022), where only C players make a decision. Precisely, at each round of the game, they can choose between action M and action J.
If both C subjects choose action J, then each C subject earns 5 Experimental Currency Units (ECU, with 1 ECU = €0.5) while subject Z earns 4 ECU. The (J;J) equilibrium is the pro-social one.
If both C subjects choose action M, then each C subject earns 7 ECU, while subject Z earns z ECU.
If C subjects do not coordinate on the same action, everyone earns 0 ECU.
Each round of the game corresponds to a specific value of z: -10; -8; -6; -4; -2; 0; 2; 4. Therefore, subjects play a total of eight rounds and are informed about the number of rounds, with the value of z that appears in random order between groups. To avoid any form of learning, no feedback will be provided at the end of each round. Only C subjects make decisions in this game. However, subjects are informed that, at the end of experiment, Z participants will be informed of all decisions made by the C participants in their group for all rounds.
We will control for group composition in the treatments and program the software to obtain:
- Groups such that all subjects already played together during the paintings game;
- Groups such that one of the C subjects and the Z subject played together during the paintings game;
- Groups such that only the C subjects played together during the paintings game.
B. Treatments:
We consider four types of experimental conditions:
- In the baseline and treatment 1 experimental conditions, C subjects will not receive any information on the other players when making their decisions.
- In treatment 2 (incomplete information condition), at each round C subjects will be informed on whether, or not, they played with the “inactive” subject during the paintings game.
- In treatment 3 (complete information condition), at each round C subjects will be informed on whether, or not, they played with the “inactive” and the other “active” subjects during the paintings game.
C. Payment:
Subjects will be informed that, at the end of the experiment, one of the rounds will be randomly selected and their payoff for that round will be added, or deduced, to a fixed dotation of 30 ECU (i.e., €15).
3) Allocation game:
After the main game, subjects, still in the same group, play an allocation game. They will be presented the same eight situations as in the previous game (in a random order), except that they will have to determine their preferred allocation of payoffs. Precisely, subjects will simply have to indicate their preferred allocation of payoffs resulting from the choice of action M or action C.
At the end of the experiment, one of the choices of the C subjects will be randomly selected in each group and the allocation decided by this subject will be implemented at the group level, and the payoffs added to the final payoff of each subject.
4) Additional variables:
Finally, we will ask subjects:
- Their beliefs (C subjects only) regarding the most frequently chosen action by other C subjects depending on their group in the paintings game (blue, orange, green). Correct beliefs will be remunerated;
- Their beliefs (Z subjects only) regarding whether other subjects in the session identified correctly the artists of the sixth pair in the paintings game. Correct beliefs will be remunerated. We ask this question to Z subjects since they do not have an active role in the experiment and we want to avoid widening the payoff gap between them and the C subjects;
- Their perceived social distance with respect to other subjects depending on their group in the paintings game (blue, orange, green), in the treatments only;
- Socio-demographic characteristics (age, gender, education).