Research On Time And Information Cost In The Evolution Of Cooperation

Cooperation usually means that individuals maximize the overall benefits at the expense of their own interests,and this phenomenon exists ubiquitously in nature and human society.The evolution of cooperation is an important mechanism in the process of social evolution.In fact,there is evidence that the existence of cooperation leads to the beginning of life on earth.On the one hand,there are some kind-hearted individuals in the population,called cooperator,who will help others by sacrificing a small part of their own interests.On the other hand,there are also some selfish individuals,called defector,who are not willing to provide any help to others and even take advantage of cooperators in order to maximize their benefits.Generally,the overall social welfare would be higher when mutual cooperation.Clearly,there are conflicts in the pursuit of the highest interests of individuals and the whole.Such a situation is defined as a social dilemma.How to understand the existence of large-scale cooperative behaviors among unrelated individuals has become one of the most challenging problems in the 21 st century.Game theory provides a powerful framework for understanding the behaviors of individuals,analyzing and researching decision making.In order to understand why a large number of cooperative behaviors exist in unfamiliar individuals,researchers use network topology to simulate the relationships between game players,each node represents an individual,and abstract the relationships between individuals into the edges of network.In recent years,many scholars have done a lot of research work in the field of network evolutionary game,which shows that the existence of cooperative behaviors is related to many aspects,such as social structure,strategy updating rules,game mechanisms in real life and so on.Because there are many factors that affect the existence of cooperation,among which the cost can directly affect the final income,it is particularly important to consider the cost in the research.Therefore,the impact of cost on evolutionary game is mainly discussed.In the information age,both time and information are extremely important to human beings.Therefore,we mainly study the impact of time cost and information cost on the evolution of cooperation among groups.In simulated experiments,two classical game models are adopted,which are snowdrift game and prisoner's dilemma.Hyperbolic network,a special scale-free network model,is used to simulate the relationships between individuals in the population.The network is modified based on the BA scale-free network model.When a new node joins,the popularity and similarity of old nodes in the network would be comprehensively weighed.The construction of hyperbolic network model is closer to the real social network,and this kind of simulation of individual relationship between populations makes the results more realistic.The main research work is as follows:First of all,the impact of time cost on the evolution of cooperation is discussed.Generally,in snowdrift game,when defectors utilize the cooperator,the defectors would get the maximum benefit without any cost.However,the passage of time is also a kind of loss.Even if the defector chooses to stay in the car and wait for the partner to shovel snow,the defector also bears the loss of time.Therefore,we think that the total cost of snow shoveling should include labor cost and time cost,and pay attention to how time cost affects the evolution of cooperation in snowdrift game.Experimental results show that no matter what kind of temptation of defect is,the larger the ratio of time cost is,the more number of cooperators can be boosted.Secondly,the impact of waiting time that defectors wait for shoveling snow is also discussed.In the classical snowdrift game,even if the defector doesn't need to shovel snow,he or she could get the benefit of going home.However,the defector has to spend time waiting for its cooperative partner to shovel snow.Time is money.Longer or shorter waiting time may bring different income difference to defectors.It is found that time cost plays a positive role in the evolution of cooperation,especially with the extension of waiting time,the number of defectors would gradually decrease.In addition,the study shows that when individuals have a higher awareness of the importance of time,more individuals choose to cooperate.Finally,we study how information cost impact the evolutionary game.In real life,people usually have to pay a certain price to get valuable information.In this work,we establish an information demander model,in which we call those individuals who are willing to pay the price for obtaining useful information as information demanders,and explore the effect of information demanders on evolutionary cooperation.Generally,we can infer the individual's strategy of the next step according to its historical behaviors.However,thanks to people have the herd mentality,they would refer to the choices of other people nearby when making decisions.D-S evidence theory is applied to integrate the proportion of cooperative strategies in the historical behaviors and the proportion of cooperators in neighbors.A probability value is calculated to speculate whether individuals choose cooperation or not.Besides,such value is called the cooperative value of the individual.The information demanders would get the cooperation value of neighbors by paying a price,and only interact with neighbors whose cooperation value are not less than its own,then update the strategy.The experimental results demonstrate that the introduction of information demanders significantly improves the level of cooperation.The higher the proportion of information demanders is,the higher the level of cooperation is.