Growing Cooperation

Georg Kirchsteiger, Tom Lenaerts and Remi Suchon

No 20326, CEPR Discussion Papers from Centre for Economic Policy Research

Abstract: Experimental evidence shows that in a repeated dilemma setting cooperation is more likely in small matching groups than in large ones. This result holds even if cooperation is an equilibrium outcome for all investigated group sizes. But what happens if small matching groups are merged to become large ones? Our paper is based on the idea that due to behavioral spillovers, a large group created by a merger of small groups is more likely to cooperate than a large group of similar size that is created directly. We tested this idea experimentally in the context of an infinitely repeated prisoner’s dilemma game. We compared the cooperation behavior of groups that result from mergers of smaller groups with the cooperation behavior of groups with constant group size. We found that cooperation levels were significantly higher in large groups that resulted from gradual growth than in large groups of the same size that were directly created. Looking at the individual behavior, we see that more subjects adopt lenient strategies when the group size increases than when it is already large from the beginning. Hence, our results confirm the idea that cooperation is much more likely to be achieved when groups grow from small to large than when large groups are formed directly.

Keywords: Prisoner's; dilemma (search for similar items in EconPapers)
JEL-codes: C73 C92 D23 D90 L22 (search for similar items in EconPapers)
Date: 2025-06
References: Add references at CitEc
Citations:

Downloads: (external link)
https://cepr.org/publications/DP20326 (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:cpr:ceprdp:20326

Ordering information: This working paper can be ordered from
https://cepr.org/publications/DP20326

Access Statistics for this paper

More papers in CEPR Discussion Papers from Centre for Economic Policy Research 33 Great Sutton Street, London EC1V 0DX, UK.
Bibliographic data for series maintained by CEPR ().