Experimental Design
[This study supercedes AEARCTR-0008445, which was previously designed to be an online experiment. The previous study was withdrawn given the easing of COVID-19 restrictions in Australia, thus giving us the opportunity to implement the experiment face-to-face in the laboratory. The size of the sessions and groups had to be changed to accommodate the capacity constraints in the laboratory. Consequently, parameters in the PG game have been modified accordingly to account for the changes to session and group sizes.]
Participants take part in 10 sequences of a public goods game with dynamic contributions. At the beginning of each sequence, participants are divided into groups of three (random rematching across sequences), and each group member is given an endowment of 30 tokens. Each sequence consists of 6 rounds where, in each round, group members can decide how much of their remaining endowment to contribute to the Group Account. Any unassigned tokens at the end of the 6th round will remain in the members' Private Accounts. Group members receive their payoffs from the Group and Private Accounts only at the end of the 6th round.
Payoffs follow the standard VCM experiment: For every token remaining in a group member's Private Account, that member receives 1 token. For every token there is in the Group Account, each group member receives 0.4 tokens.
The main treatments vary on the information that group members receive at the end of each round of the sequence, with feedback being either time-based or milestone-based. Where feedback is milestone-based, we will also vary the intervals of the milestones.