Emergence of group cooperation in public goods game on regular small-world network

The regular small-world network, which contains the properties of small-world network and regular network, has recently received substantial attention and has been applied in researches on 2-person games. However, it is a common phenomenon that cooperation always appears as a group behavior. In order to investigate the mechanism of group cooperation, we propose an evolutionary multi-person game model on a regular small-world network based on public goods game theory. Then, to make a comparison of frequency of cooperation among different networks, we carry out simulations on three kinds of networks with the same configuration of average degree: the square lattice, regular small-world network and random regular network. The results of simulation show that the group cooperation will emerge among these three networks when the enhancement factor r exceeds a threshold. Furthermore, time required for full cooperation on regular small-world network is slightly longer than the other networks, which indicates that the compact interactions and random interactions will promote cooperation, while the longer-range links are the obstacles in the emergence of cooperation. In addition, the cooperation would be promoted further by enhancing the random interactions on regular small-world network.     

无标度网络中的公共物品博弈

研究了无标度网络中的公共物品博弈行为受网络节点异质性以及噪声的影响.通过数值模拟,发现节点的异质性有利于网络中合作的涌现,而噪声对博弈行为的影响还取决于其它因素.     

小世界网络中的公共物品博弈

研究了小世界网络中的公共物品博弈,分析了噪声以及网络节点的异质性对博弈行为的影响．我们发现,网络的小世界特性以及网络中的噪声对博弈过程中合作的涌现起抑制作用,而网络节点的异质性则对博弈过程中合作的涌现起促进作用．我们用平均场理论对得到的数值模拟的结果进行了对比和分析．     

Maintenance of cooperation in a public goods game: A new decision-making criterion with incomplete information

Hardin’s "The Tragedy of the Commons" prophesies the inescapable collapse of many human enterprises.The emergence and abundance of cooperation in animal and human societies is a challenging puzzle to evolutionary theory.In this work,we introduce a new decision-making criterion into a voluntary public goods game with incomplete information and choose successful strategies according to previous payoffs for a certain strategy as well as the risk-averse benefit.We find that the interest rate of the common pool and the magnitude of memory have crucial effects on the average welfare of the population.The appropriate sense of individuals’ innovation also substantially influences the equilibrium strategies distribution in the long run.     

Mobility promotes and jeopardizes biodiversity in rock-paper-scissors games

Biodiversity is essential to the viability of ecological systems. Species diversity in ecosystems is promoted by cyclic, non-hierarchical interactions among competing populations. Central features of such non-transitive relations are represented by the 'rock-paper-scissors' game, in which rock crushes scissors, scissors cut paper, and paper wraps rock. In combination with spatial dispersal of static populations, this type of competition results in the stable coexistence of all species and the long-term maintenance of biodiversity. However, population mobility is a central feature of real ecosystems: animals migrate, bacteria run and tumble. Here, we observe a critical influence of mobility on species diversity. When mobility exceeds a certain value, biodiversity is jeopardized and lost. In contrast, below this critical threshold all subpopulations coexist and an entanglement of travelling spiral waves forms in the course of time. We establish that this phenomenon is robust; it does not depend on the details of cyclic competition or spatial environment. These findings have important implications for maintenance and temporal development of ecological systems and are relevant for the formation and propagation of patterns in microbial populations or excitable media.     

Spatial games and the maintenance of cooperation in an asymmetric Hawk-Dove game

Classical theories explaining the evolution of cooperation often rely on the assumption that the involved players are symmetrically interacted.However,in reality almost all well-documented cooperation systems show that cooperative players are in fact asymmetrically interacted and that this dynamic may greatly affect the cooperative behavior of the involved players.Here,we developed several models based on the most well known spatial game of the Hawk-Dove game,while also considering the effects of asymmetric interaction.Such asymmetric games possess four kinds of strategies:cooperation or defection of strong player and cooperation or defection of weak player.Computer simulations showed that the probability of defection of the strong player decreases with decreasing the benefit to cost ratio,and that all kinds of strategy will be substituted by cooperation on behalf of the strong player if the benefit to cost ratio is sufficiently small.Moreover,weak players find it difficult to survive and the surviving weak players are mostly defectors,similar to the Boxed Pigs game.Interestingly,the patterns of kinds of strategies are chaotic or oscillate in some conditions with the related factors.     

Variation in behaviour promotes cooperation in the Prisoner's Dilemma game

The Prisoner's Dilemma game is widely used to investigate how cooperation between unrelated individuals can evolve by natural selection. In this game, each player can either 'cooperate' (invest in a common good) or 'defect' (exploit the other's investment). If the opponent cooperates, you get R if you cooperate and T if you defect. If the opponent defects, you get S if you cooperate and P if you defect. Here T > R > 0 and P > S, so that 'defect' is the best response to any action by the opponent. Thus in a single play of the game, each player should defect. In our game, a fixed maximum number of rounds of the Prisoner's Dilemma game is played against the same opponent. A standard argument based on working backwards from the last round shows that defection on all rounds is the only stable outcome. In contrast, we show that if extrinsic factors maintain variation in behaviour, high levels of co-operation are stable. Our results highlight the importance of extrinsic variability in determining the outcome of evolutionary games.     

Social networks and cooperation in hunter-gatherers

Social networks show striking structural regularities, and both theory and evidence suggest that networks may have facilitated the development of large-scale cooperation in humans. Here, we characterize the social networks of the Hadza, a population of hunter-gatherers in Tanzania. We show that Hadza networks have important properties also seen in modernized social networks, including a skewed degree distribution, degree assortativity, transitivity, reciprocity, geographic decay and homophily. We demonstrate that Hadza camps exhibit high between-group and low within-group variation in public goods game donations. Network ties are also more likely between people who give the same amount, and the similarity in cooperative behaviour extends up to two degrees of separation. Social distance appears to be as important as genetic relatedness and physical proximity in explaining assortativity in cooperation. Our results suggest that certain elements of social network structure may have been present at an early point in human history. Also, early humans may have formed ties with both kin and non-kin, based in part on their tendency to cooperate. Social networks may thus have contributed to the emergence of cooperation.     

Volunteering leads to rock-paper-scissors dynamics in a public goods game

Collective efforts are a trademark of both insect and human societies. They are achieved through relatedness in the former and unknown mechanisms in the latter. The problem of achieving cooperation among non-kin has been described as the 'tragedy of the commons', prophesying the inescapable collapse of many human enterprises. In public goods experiments, initial cooperation usually drops quickly to almost zero. It can be maintained by the opportunity to punish defectors or the need to maintain good reputation. Both schemes require that defectors are identified. Theorists propose that a simple but effective mechanism operates under full anonymity. With optional participation in the public goods game, 'loners' (players who do not join the group), defectors and cooperators will coexist through rock-paper-scissors dynamics. Here we show experimentally that volunteering generates these dynamics in public goods games and that manipulating initial conditions can produce each predicted direction. If, by manipulating displayed decisions, it is pretended that defectors have the highest frequency, loners soon become most frequent, as do cooperators after loners and defectors after cooperators. On average, cooperation is perpetuated at a substantial level.     

基于“绿箱”政策的农村公共产品供给研究

公共产品供给不足严重制约了农业经济的可持续发展。目前我国农村公共产品供给的制约因素主要是：公共财政投入不足;尚未建立多元的供给机制;公共政策的困境等。在“绿箱”政策框架内扩大公共产品供给,应加大公共财政对农村基础设施建设的支持力度;按WTO规则界定政府职能;制定有效的公共政策,刺激公共产品的私人供给。     

集体风险投资公共品博弈的种群演化动力学的研究

集体目标的完成需要多个个体的参与贡献。然而每个个体都想最大化自己的利益,因此,研究贡献行为在自私个体中产生并广泛传播成了公共品博弈动力学的核心问题。通过建立一个具有集体风险的公共品博弈的理论模型,加入了增长因子这个因素,更加贴近真实,动力学的演化特征更加丰富,并借助复制动力学的演化分析,结果显示较高风险,较高增长回报下有利于合作的涌现。同时,个体的初始财富、集体目标、合作代价、参与博弈的个体数目等因素也会对种群产生影响。     

公关人员的社会行为失范分析

随着社会经济的发展，公关人员作为一种职业受到企业和公司的青睐，但是目前公关人员的社会行为还存在着失范的现象，一方面是公关人员的庸俗思想；另一方面公关人员的“双边人”的角色存在着对立。本文从韦伯的社会行动类型理论出发，对公关人员的失范行为进行工具理性和价值理性的分析。     

基于"绿箱"政策的农村公共产品供给研究

公共产品供给不足严重制约了农业经济的可持续发展.目前我国农村公共产品供给的制约因素主要是:公共财政投入不足;尚未建立多元的供给机制;公共政策的困境等.在"绿箱"政策框架内扩大公共产品供给,应加大公共财政对农村基础设施建设的支持力度;按WTO规则界定政府职能;制定有效的公共政策,刺激公共产品的私人供给.     

社会资本与构建政府信任合作体系

导致政府失信的原因是多方面的，期望它提供公共物品并不能解决根本问题，因此，构建政府信任合作体系成为关键。通过建立社会声誉机制、社会激励机制以及对话会晤协商机制可以逐渐构建起政府信任体系。     

校企合作开发公共体育课程校外实践活动基地研究

采用文献资料、实验研究等方法,探讨学校和企业协作开发公共体育课程学生校外实践活动基地的动因、途径和效果。结果表明：通过校外体育实践活动与校内课程教学相结合,有效提高学生体育兴趣和能力;实验组身体素质指标、运动技能指标优于对照组;合作开发实践活动基地能够实现学校和企业的共赢。     

我国城市居民对北京奥运会的社会心理期待研究

以我国部分城市居民对北京奥运会举办成功主要标准的认知状况为依托,运用文献资料调研、专家访谈、问卷调查、数理统计等方法对我国城市居民对北京奥运会的社会心理期待进行了探讨.结果表明:我国城市居民对北京奥运会举办成功的主要标准有较高的社会认同度,人们对北京奥运会提升国家威望、凝聚民心、推动经济发展、促进民众健康等效能具有较高的心理期待,而对我国的竞技成绩高低及奥运本身赢利与否等问题的关注度则相对较低.     

科技引领未来，合作推动发展——中国科学院“十二五”院地合作发展战略

通过"十一五"期间知识创新工程的实施,中国科学院已经成为具有国际先进水平的科学研究基地、培养造就高级科技人才的基地和促进我国高技术产业发展的基地,科技创新能力全面提升,为在改革创新、支撑发展、引领未来中发挥火车头作用奠定了坚实的基础。院地合作是促进中国科学院与国家技术创新体系和区域创新体系紧密结合,加快科技成果转移转化的重要途径,是中国科学院改革创新、服务国家、造福人民的重要使命,是激发科技创新活力,实现中国科学院可持续发展的动力源泉。为更好指导和推进"十二五"院地合作工作,根据中国科学院"创新2020"规划的总体部署,结合区域经济与产业发展的实际科技需求,研究编制《中国科学院院地合作发展规划(2011-2015年)》。     

基于满意度的区间型多人合作对策在供应链产品合作创新利益分配中的应用

针对区间支付值可能具有嵌套、重叠和(或)包含关系的供应链产品合作创新利益分配问题,定义了基于满意度的区间数排序指标.据此提出区间型多人合作对策的区间值核心解概念和相应的求解方法,并与区间Shapley值求解方法作对比分析.通过实例验证了所提方法的可行性和有效性.     

农村公共产品供给的一个理论性解释——基于集体行动和交易成本的分析

我国农村公共产品供给存在许多问题。长期以来,对农村公共产品供给问题的研究缺乏创新。“交易成本”和“集体行动的逻辑”这两个分析工具可以很好地解释农村公共产品供给中出现的问题。降低交易成本,提高自愿性集体行动的可组织程度,是完善农村公共产品供给体制的根本途径。