Power of Joint Decision-Making in a Finitely-Repeated Dilemma

A rich body of literature has proposed that pairs behave significantly differently from individuals due to a number of reasons such as group polarization. This paper experimentally compares cooperation behaviors between pairs and individuals in a finitely-repeated two-player public goods game (continuous prisoner’s dilemma game). We show that pairs contribute significantly more than individuals to their group accounts. Especially, when two pairs are matched with each other for the entire periods, they successfully build long-lasting cooperative relationships with their matched pairs. Our detailed analyses suggest that the enhanced cooperation behavior of pairs may be driven by (a) the mere fact that they have partners when they make decisions, (b) group polarization – those who initially prefer to contribute smaller amounts are more affected by the partners in their pairs, and (c) stronger conditional cooperation behavior of pairs to their matched pairs.