The impact of expressing willingness to cooperate on cooperation in public goods game

In present work, we regard the expressing willingness to cooperate as a kind of signal and introduce it in public goods game (PGG). For the receivers, they only trust the credible signal. For the senders, on the one hand they need to maintain their credibility, on the other hand they may be tempted to cheat. Therefore, we propose different types of rule of decision-making for receivers and senders of cooperative signal. We aim to study the impact of expressing willingness to cooperate under the condition of combining two types of behavior. Numerical simulations prove that expressing willingness to cooperate can promote cooperation. Further researches show that high credibility threshold can effectively suppress false signals and help the evolution of cooperation. However, the maximum cooperation rate depends on the value of expected image score. Moreover, when expected image score is low, the cooperation rate is more sensitive to the change in cost of expressing the willingness to cooperate. The possible reason for our analysis is that the high cost puts opportunistic players at a disadvantage in evolution.