Cycles of Strategies and Changes of Distribution in Public Goods Game : An Experimental Investigation

In this communication, a simple mechanism in the optional public goods game is experimentally investigated using two experimental settings; and first time, the cyclic strategy pattern in full state space is demonstrated by means of velocity. It is, furthermore, elaborated that the strategies of cooperation, defection and nonparticipant form a Rock-Paper-Scissors type cycle, and the cycle of three strategies are persistent over 200 rounds. This cycle is very similar to the cycle given by evolutionary dynamics e.g. replicator dynamics. The mechanism that nonparticipant can sustain cooperation is driven by the Rock-Paper-Scissors type of cyclic dominance in the three strategies. That is, if the cycle is existent, the cooperation will always sustain. Meanwhile, the distribution of social states changes in the state space and from cooperation as the most frequent strategy to defection and, from defection to nonparticipant, forms a clear rotation path in a long run. These results seem to implicate that the evolutionary dynamics has ability to capture the real dynamics applying not only on biosphere, but also on human society