The emergence of cooperation-extortion alliance on scale-free networks with normalized payoff

¹ CompleX Lab, School of Computer Science and Engineering, University of Electronic Science and Technology of China - Chengdu 611731, China
² Big Data Research Center, University of Electronic Science and Technology of China - Chengdu 611731, China
³ Institute of Computational Physics and Complex Systems, Lanzhou University - Lanzhou, Gansu 730000, China

^(a) rongzhh@gmail.com (corresponding author)
^(b) eric0724@gmail.com (corresponding author)

Received: 14 May 2018
Accepted: 25 June 2018

Abstract

Based on the Prisoner's Dilemma game, this paper investigates the evolution of extortion behavior with cooperation and defection strategies on the Barabási-Albert (BA) scale-free network under the normalized payoff framework. Using Monte Carlo simulations, we show that the cooperation-extortion alliance emerges, and extortioners can act as catalysts to help cooperators survive on the scale-free network. Moreover, we find the non-trivial influence of the extortion factor on the evolution of cooperation, which implies that there exists an optimal value of the extortion factor with which the cooperation-extortion alliance is mostly favored and may defeat defectors on the networks with the normalized payoff framework.