Modeling cooperation among self-interested agents: a critique

This paper reviews recent attempts to model cooperation in groups of self-interested unrelated individuals. It concludes that no empirically plausible model has been developed, and the economist's quest for an explanation of human prosociality in terms of self-interested agents has not been successful. We show that the equilibrium criteria employed in standard game-theoretic models have no attractive dynamic properties, and the mechanisms deployed in these models are not generally seen in empirical examples of cooperative groups. We also show that these models are not robust to plausible rates of signaling error and mutation. We present an alternative, involving strongly reciprocal agents, that satisfies all the requirements for a dynamically stable model of cooperation.     

Markov chain Monte Carlo methods for high dimensional inversion in remote sensing

Summary.  We discuss the inversion of the gas profiles (ozone, NO₃, NO₂, aerosols and neutral density) in the upper atmosphere from the spectral occultation measurements. The data are produced by the 'Global ozone monitoring of occultation of stars' instrument on board the Envisat satellite that was launched in March 2002. The instrument measures the attenuation of light spectra at various horizontal paths from about 100 km down to 10–20 km. The new feature is that these data allow the inversion of the gas concentration height profiles. A short introduction is given to the present operational data management procedure with examples of the first real data inversion. Several solution options for a more comprehensive statistical inversion are presented. A direct inversion leads to a non-linear model with hundreds of parameters to be estimated. The problem is solved with an adaptive single-step Markov chain Monte Carlo algorithm. Another approach is to divide the problem into several non-linear smaller dimensional problems, to run parallel adaptive Markov chain Monte Carlo chains for them and to solve the gas profiles in repetitive linear steps. The effect of grid size is discussed, and we present how the prior regularization takes the grid size into account in a way that effectively leads to a grid-independent inversion.     

The repeated public goods game: A solution using Tit-for-Tat and the Lindahl point

This paper demonstrates how a repeated public goods problem may be solved by using Tit-for-Tat (TFT) on the Lindahl point. The general solution is developed; geometric and numerical examples are offered.I wish to thank an anonymous reviewer for very helpful comments on earlier drafts of this paper.     

古代突厥语民族的民间竞技与游戏——以《突厥语大词典》和《福乐智慧》为例

文章主要收集了《突厥语大词典》和《福乐智慧》中的民间竞技与游戏的语言材料,通过古代突厥语民族的赛马、射箭、马球、达瓦孜、投掷等体育竞技与游戏,试图再现他们当时的社会生活概貌。     

Boundary Spaces

While shows like The X-Files and 24 have merged conspiracy theories with popular science (fictions), some video games have been pushing the narrative even further. Electronic Art's Majestic game was released in July 2001 and quickly generated media buzz with its unusual multi-modal gameplay. Mixing phone calls, faxes, instant messaging, real and "fake' websites, and email, the game provides a fascinating case of an attempt at new directions for gaming communities. Through story, mode of playing, and use of technology, Majestic highlights the uncertain status of knowledge, community and self in a digital age; at the same time, it allows examination of alternative ways of understanding games' role and purpose in the larger culture. Drawing on intricate storylines involving government conspiracies, techno-bio warfare, murder and global terror, players were asked to solve mysteries in the hopes of preventing a devastating future of domination. Because the game drew in both actual and Majestic-owned/-designed websites, it constantly pushed those playing the game right to borders where simulation collides with " factuality'. Given the wide variety of "legitimate' conspiracy theory, alien encounters and alternative science web pages, users often could not distinguish when they were leaving the game's pages and venturing into " real' World Wide Web sites. Its further use of AOL's instant messenger system, in which gamers spoke not only to bots but to other players, pushed users to evaluate constantly both the status of those they were talking to and the information being provided. Additionally, the game required players to occupy unfamiliar subject positions, ones where agency was attenuated, and which subsequently generated a multi-layered sense of unease among players. This mix of authentic and staged information in conjunction with technologically mediated roles highlights what are often seen as phenomenon endemic to the Internet itself; that is, the destabilization of categories of knowing, relating, and being.     

审视经济全球化

由于各国经济发展的不平衡,经济全球化的当代特征表现为三角化、区域一体化和跨国公司的迅速崛起。经济全球化正在改变现有政治格局,推动世界政治朝全球性方向演进并形成全球性的治理机构或协调治理形式。在以发达国家为主导、跨国公司为主要动力的经济全球化过程中,中国作为发展中国家在国际竞争方面处于弱势,这要靠全党全民运用自己的智慧和力量,利用自己已经具备的各种有利条件去应对全球化的挑战。从人类社会经济形态演进的自然历史过程看,经济全球化不过是资本主义的社会化生产和市场全球性扩张的新的历史阶段。从马克思的立场看,全球化将会是资本主义时代的终结,并为社会主义社会的到来做好准备,随全球化而来的将是一个更加美好的新世界。     

Far-sighted equilibria in 2 × 2, non-cooperative,repeated games

Consider a two-person simultaneous-move game in strategic form. Suppose this game is played over and over at discrete points in time. Suppose, furthermore, that communication is not possible, but nevertheless we observe some regularity in the sequence of outcomes. The aim of this paper is to provide an explanation for the question why such regularity might persist for many (i.e., infinite) periods.Each player, when contemplating a deviation, considers a sequential-move game, roughly speaking of the following form: if I change my strategy this period, then in the next my opponent will take his strategy b and afterwards I can switch to my strategy a, but then I am worse off since at that outcome my opponent has no incentive to change anymore, whatever I do. Theoretically, however, there is no end to such reaction chains. In case that deviating by some player gives him less utility in the long run than before deviation, we say that the original regular sequence of outcomes is far-sighted stable for that player. It is a far-sighted equilibrium if it is far-sighted stable for both players.     

人际信任的自我削弱与熟人社会变迁

接续阶层分化的研究路径,从农民互惠博弈内生视角出发,构建"人际信任-熟人社会"的分析框架,以揭示熟人社会变迁的微观动力机制。研究认为,小农经济的生产形态与农耕文明时期低社会生产力水平以致农民长期面临生存威胁之间的张力,催生了广布于乡村社会的互惠网络,农民人际信任的自我增强与经济互助及道德声誉制度的自我实施相互作用,生成并维系传统熟人社会及其发展。市场性的输入以经济分化和农民离村为着力点打破了这一继替格局。农民摆脱生存威胁后,其互惠付出意愿降低,进而影响博弈双方的行为选择。当信任的自我削弱使农民的制度化信念发生质变时,熟人社会逐步解体趋势难以逆转。流动性社会中,基于连接性社会网络建立新型农村社区,是乡村社会发展的重要方向。     

Coherent decision analysis with inseparable probabilities and utilities

This article explores the extent to which a decision maker's probabilities can be measured separately from his/her utilities by observing his/her acceptance of small monetary gambles. Only a partial separation is achieved: the acceptable gambles are partitioned into a set of belief gambles, which reveals probabilities distorted by marginal utilities for money, and a set of preference gambles, which reveals utilities reciprocally distorted by marginal utilities for money. However, the information in these gambles still enables us to solve the decision maker's problem: his/her utility-maximizing decision is the one that avoids arbitrage (i.e., incoherence or Dutch books).     

大学生足球运动损伤的调查分析

运用调查法了解学生在足球运动中损伤情况,并提出相应的预防措施。