Volume 80, Number 1, October 2007
Article Number 18002
Number of page(s) 4
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 11 September 2007
EPL, 80 (2007) 18002
DOI: 10.1209/0295-5075/80/18002

Cooperative behavior in a model of evolutionary snowdrift games with N-person interactions

D. F. Zheng1, H. P. Yin2, C. H. Chan2 and P. M. Hui2

1  Zhejiang Institute of Modern Physics and Department of Physics, Zhejiang University Hangzhou 310027, PRC
2  Department of Physics and Institute of Theoretical Physics, The Chinese University of Hong Kong Shatin, Hong Kong, China

received 28 June 2007; accepted in final form 17 August 2007; published October 2007
published online 11 September 2007

We propose a model of evolutionary snowdrift game with N-person interactions and study the effects of multi-person interactions on the emergence of cooperation. An exact N-th$\hbox{--} $order equation for the equilibrium density of cooperators x* is derived for a well-mixed population using the approach of replicator dynamics. The results show that the extent of cooperation drops with increasing cost-to-benefit ratio and the number N of interaction persons in a group, with x*~ 1/N for large N. An algorithm for numerical simulations is constructed for the model. The simulation results are in good agreement with theoretical results of the replicator dynamics.

87.23.Kg - Dynamics of evolution.
02.50.Le - Decision theory and game theory.
89.75.Fb - Structures and organization in complex systems.

© Europhysics Letters Association 2007