TY - JOUR
T1 - Dynamic utility
T2 - The sixth reciprocity mechanism for the evolution of cooperation: The sixth reciprocity rule
AU - Ito, Hiromu
AU - Tanimoto, Jun
N1 - Funding Information:
Ethics. The authors confirm that the study did not use humans or animals. Data accessibility. The authors confirm that the article has no data. Authors’ contribution. H.I. and J.T. conceived the study. H.I. generated the figures. H.I. and J.T. wrote the manuscript. Competing interests. The authors declare that they have no competing interests. Funding. This work was supported by the JSPS KAKENHI (grant nos. 17J06741 and 17H04731 to H.I., and 18K18924 and 19KK0262 to J.T.). Acknowledgements. We thank Prof. Jin Yoshimura for valuable feedback and discussions.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - Game theory has been extensively applied to elucidate the evolutionary mechanism of cooperative behaviour. Dilemmas in game theory are important elements that disturb the promotion of cooperation. An important question is how to escape from dilemmas. Recently, a dynamic utility function (DUF) that considers an individual's current status (wealth) and that can be applied to game theory was developed. The DUF is different from the famous five reciprocity mechanisms called Nowak's five rules. Under the DUF, cooperation is promoted by poor players in the chicken game, with no changes in the prisoner's dilemma and stag-hunt games. In this paper, by comparing the strengths of the two dilemmas, we show that the DUF is a novel reciprocity mechanism (sixth rule) that differs from Nowak's five rules. We also show the difference in dilemma relaxation between dynamic game theory and (traditional) static game theory when the DUF and one of the five rules are combined. Our results indicate that poor players unequivocally promote cooperation in any dynamic game. Unlike conventional rules that have to be brought into game settings, this sixth rule is universally (canonical form) applicable to any game because all repeated/evolutionary games are dynamic in principle.
AB - Game theory has been extensively applied to elucidate the evolutionary mechanism of cooperative behaviour. Dilemmas in game theory are important elements that disturb the promotion of cooperation. An important question is how to escape from dilemmas. Recently, a dynamic utility function (DUF) that considers an individual's current status (wealth) and that can be applied to game theory was developed. The DUF is different from the famous five reciprocity mechanisms called Nowak's five rules. Under the DUF, cooperation is promoted by poor players in the chicken game, with no changes in the prisoner's dilemma and stag-hunt games. In this paper, by comparing the strengths of the two dilemmas, we show that the DUF is a novel reciprocity mechanism (sixth rule) that differs from Nowak's five rules. We also show the difference in dilemma relaxation between dynamic game theory and (traditional) static game theory when the DUF and one of the five rules are combined. Our results indicate that poor players unequivocally promote cooperation in any dynamic game. Unlike conventional rules that have to be brought into game settings, this sixth rule is universally (canonical form) applicable to any game because all repeated/evolutionary games are dynamic in principle.
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U2 - 10.1098/rsos.200891rsos200891
DO - 10.1098/rsos.200891rsos200891
M3 - Article
AN - SCOPUS:85091239075
SN - 2054-5703
VL - 7
JO - Royal Society Open Science
JF - Royal Society Open Science
IS - 8
M1 - 200891
ER -