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Discrete Dynamics in Nature and Society
Volume 2014 (2014), Article ID 907052, 8 pages
http://dx.doi.org/10.1155/2014/907052
Research Article

Effects of Empty Sites on Cooperation in the Prisoner’s Dilemma Game Based on Social Diversity

1Department of Physics, Langfang Teachers College, Langfang 065000, China
2Department of Physics, Tianjin University of Technology, Tianjin 300191, China

Received 19 July 2013; Revised 30 November 2013; Accepted 3 December 2013; Published 14 January 2014

Academic Editor: Gualberto Solís-Perales

Copyright © 2014 Wang Liming and Feng Wu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We study the effects of empty sites in the prisoner’s dilemma game based on social diversity by introducing some empty sites into a square lattice. The results reveal that the empty sites dramatically enhance the cooperation level for a wide range of temptation to defection values if two types of players coexist. By calculating the chances of different type-combinations of the players located on the square lattice, we find that there is an intermediate region where five social ranks are induced to satisfy the certain rank distributions and the cooperation level is significantly enhanced. Moreover, simulation results also show that the moderate gaps among the social ranks can favor cooperation for a larger occupation density.