利他行为及其经济学意义——兼与叶航等探讨

本文指出了叶航(2005)和叶航、汪丁丁、罗卫东(2005)建立的“利他行为演化均衡”模型的错误,重新梳理了利他行为与经济学的关系。现代经济学的分析框架并不排斥利他偏好,利他行为难以进入经济学实证分析,主要是由于利他行为难以量化。人类利他行为是生物进化和社会发展的综合产物,道德情感和道德规范在其中起了关键性的作用,但这并不妨碍经济学把利他偏好当作人性的一部分。经济学可以通过解释道德情感的进化根源、道德规范的形成机制以及道德规范对个人行为方式的影响,来解释人为什么有利他行为。     

运用"经济人--道德人"假说对合作行为的分析

对于合作的分析,现代经济学是以"经济人"假说作为分析前提的。这种分析在解释合作最重要的特征——互惠利他所包含的有意识的利他行为时存在着"贫困性"。虽然在良好的法律和制度保证下,"经济人"也会促进公共利益或社会福利,但这种利他行为是无意识的。在"经济人"假说分析的基础上,结合"道德人"假说可以对合作行为有一个很好的解释,尤其是对于"囚犯困境"的解释。     

行为博弈的互惠利他行为理论研究的进展

利他行为是人类社会活动中的一种现象。随着行为经济学特别是行为博弈和实验经济学的发展,有关利他行为的研究在近几十年得到较多的深入研究和认识。该文在简要论述利他行为社会心理学、生物学中已有的研究成果基础上,着重阐述了经济学研究利他行为的理论、方法和进展。     

从利他性到社会理性——利他主义经济学研究的一个综合观点

利他主义经济学的研究非常繁杂,缺乏一个统一的理论.本文提出利他行为的方向性问题,分析了基因决定论的局限,综合研究了基因选择、个体选择以及群体选择对人类个体利他行为的影响,从而形成了利他性研究的一个综合性理论.在解决利他行为方向性问题的基础上,发现人类利他行为实质上是人的社会性的体现,从而提出了社会理性概念,扩展了利他主义经济学的研究.     

有限理性、规范内化与利他行为:一个演化视角

本文沿着有限理性的理论进路,通过规范内化对利他行为做出一个解释。以往的理论通过规范提供的外在奖惩解释利他行为,但无法解释在外在奖惩不存在的情况下出现的纯利他行为。本文认为,这些利他行为可以通过规范内化来解释,而后者则是有限理性的一个自然结果。为了阐明规范内化如何产生,本文给出了一个形式化的复制者动态,其结果表明,在考虑有限理性的前提下,社会交往越复杂,人类处理复杂性的认知能力越有限,规范内化出现的可能性就越大。针对复制者动态模型的局限,本文还运用基于行为主体建模对规范内化过程进行了模拟。模拟结果显示,当人类理性计算能力相对于社会生活的复杂程度越小,规范内化出现的可能性越大,该结果与之前分析结论一致。本文的分析结果再次支持了Herbert Simon对利他行为的解释,即利他行为是人类有限理性的结果,虽然利他行为自身减少个体适应性,但由于它是规范内化所产生的一个自然结果,所以利他行为因为规范内化所具有的适应性而留存。     

利他行为对信息系统集成知识创新的影响

针对知识的非消耗性属性,以利他行为的客观存在性为前提,将知识创新中的利他行为划分为知识共享利他行为和知识创新成本分担利他行为,针对两种情形构建知识创新模型,通过模型演算分析利他行为对知识创新绩效的影响。指出:利他行为对知识创新效益的影响可能为正也可能为负——有助于提升知识创新度,但也会促使"搭便车"行为发生,即知识收益分享比例和知识创新成本分担比例都存在闵值,小于该闵值时知识创新整体效益将提升;利他行为受合作主体的知识积累效率和知识创新努力程度的影响。最后,以厦门区域医疗协同平台为例,阐述了信息系统集成知识创新中的利他行为。     

利他偏好的内生模型及其经济学解释

利他行为对自利人性假设的挑战,要求经济学必须把偏好进行内生化处理。笔者首先构建了一个利他偏好内生模型,使得人类行为统一于效用最大化模式并具有了内在一致的规律性和可预测性;然后对利他偏好内生模型的合理性进行了解释。笔者认为,与利己行为不同,行为主体不是从利他行为后果而是从利他行为本身获得效用;通过整体间的生存适应性补偿机制,利他者不仅可以战胜利己者得以存在和持续,而且利他惩罚行为还为人类走出囚徒困境提供了有力的保证。     

利他行为的经济学解释

利他行为可以分为亲缘利他、互惠利他与纯粹利他三种形式。对前两种利他行为,生物学已经给出了较为圆满的解释,而且,这种解释也是符合经济学原理的。关于纯粹利他,生物学存在着很大争论,至今没有圆满的解释。本文在“合作剩余”和“生物演化稳定策略”(ESS)的基础上,提出一个能够解释地粹利他行为的模型．并利用脑科学的最新研究成果对这一行为内在的激励机制作出了说明。     

利他偏好的内生模型及其经济学解释

利他行为对自利人性假设的挑战，要求经济学必须把偏好进行内生化处理。笔者首先构建了一个利他偏好内生模型，使得人类行为统一于效用最大化模式并具有了内在一致的规律性和可预测性；然后对利他偏好内生模型的合理性进行了解释。笔者认为，与利己行为不同，行为主体不是从利他行为后果而是从利他行为本身获得效用；通过整体间的生存适应性补偿机制，利他者不仅可以战胜利己者得以存在和持续，而且利他惩罚行为还为人类走出囚徒困境提供了有力的保证。     

利他行为的治理机制及效率研究

本文从资源配置的视角来研究家庭中普遍存在的利他行为,由于利他行为本身并无法自动实现家庭资源配置的帕累托最优,有必要采取相应的治理机制来消除利他行为带来的负面效应。本文在分析利他行为治理机制两难困境的基础上,进一步探析了信息不对称以及自我控制水平对治理机制效率的影响,研究认为不存在一种适用于所有状态的完美治理机制,应根据不同的情境引入相机选择的动态治理机制,以最大程度发挥利他行为配置资源的正面效应。本文最后在分析家庭利他行为治理机制的基础上,对当前民营家族制企业的治理机制也提出了相应启示。     

Group Selection and the Limits to Altruism

Several evolutionary mechanisms have been identified in the literature that would generate altruism in humans. The most powerful (except for kin selection) and most controversial is group selection, as recently analyzed by Sober & D.S. Wilson. I do not take a stand on the issue of the existence of group selection. Instead, I examine the level of human altruism that could exist if group selection were an engine of human evolution. For the Sober & Wilson mechanism to work, groups practicing altruism must grow faster than other groups. I call altruistic behavior that would lead to faster growth efficient altruism. This often consists of cooperation in a prisoner's dilemma. ltruistic acts such as helping a temporarily hungry or injured person would qualify as efficient altruism. Efficient altruism would also require monitoring recipients to avoid shirking. Utilitarianism would be an ethical system consistent with efficient altruism, but Marxism or the Rawlsian system would not. Discussions of efficient altruism also help understand intuitions about fairness. We perceive those behaviors as fair that are consistent with efficient altruism. It is important to understand that, even if humans are selected to be altruistic, the forms of altruism that might exist must be carefully considered and ircumscribed.     

The Human Adaptation for Culture and its Behavioral Implications

During phylogeny, man adapted for culture in ways other primates did not. This key adaptation is the one that enabled humans to understand other individuals as intentional agents like the self. This genetic event opened the way for new and powerful cultural processes but did not specify the detailed outcomes of behavior we see today. It just provided the basis for cultural evolution that, with no further genetic events, enabled the distinctive characteristics of human cognition. These capabilities can explain the motivational underpinnings of a variety of human inclinations and behaviors, such as a tendency toward cooperation, altruism, or fairness. This revised version was published online in July 2006 with corrections to the Cover Date.     

It pays to do good,but not to do more good than it pays: A note on the survival of altruism

Recently Becker and Hirshleifer have attempted to explain the survival of altruism. Altruism ‘pays’ in their framework because it permits mutual cooperation or exchange to take place. This paper shows that these arguments are invalid. This case is that in any environment where altruism pays there is always an egoistic strategy called cooperation egoism — which yields an even higher return. In equilibrium, this will be anticipated so that, while altruism may pay off in a disequilibrium situation, in equilibrium egoism and not altruism has survival value.     

Toward an Evolutionary and Moral Science

Thorstein Veblen asked in 1898 why economics is not an evolutionary science; he also proposed a Darwinian paradigm shift for economics. Among the implications reviewed here was his claim that Darwinian principles applied to social entities as well as to biological phenomena. It is also argued that economists have additional reasons for taking Darwinian evolution seriously. Recent work on the evolution of altruism, cooperation and morality show that we are on the brink of developing an evolutionary-grounded theory of human motivation that breaks from the selfish utility-maximizer lambasted by Veblen. This new theory accepts a biological as well as a cultural foundation for moral dispositions. As noted here, the neglected British institutional economist John A. Hobson — who was an acquaintance of Veblen — foreshadowed this approach.     

The Bioeconomics of Cooperation

When transactions and information are costly and exchange is non-simultaneous, ‘institutions matter’. They matter because exchange under these circumstances subjects the participants to potentially harmful behaviors by other participants, among which are: opportunistic behavior, agency, the free-rider problem, cheating, moral hazard, and adverse selection. Institutions constrain these behaviors, allowing the participants to take advantage of the gains from trade and specialization, and thereby facilitating cooperation. Individuals adhere to institutional rules because they gain by doing so. Because the individual gains are inseparable from the structure of the institutions, the institutions themselves necessarily become the focus of the analysis—as we see in the new institutional economics (NIE). The new group selection position in biology involves a similar shift in focus from the level of the individual to the group when studying the evolution of altruism. But some of the proponents of group selection go further, arguing that altruism in biology evolves because it is in the interest of the group, but not the individual. In fact, group level analysis is necessary in biology, as in the NIE, because it allows for the discovery of ‘institutions’ that constrain cheating, opportunistic behavior, etc., thereby making participation in the group in the long-run self-interest of the individual. This revised version was published online in August 2006 with corrections to the Cover Date.     

Individual characteristics and behavior in repeated games: an experimental study

Using a laboratory experiment, we investigate whether a variety of behaviors in repeated games are related to an array of individual characteristics that are popular in economics: risk attitude, time preference, trust, trustworthiness, altruism, strategic skills in one-shot matrix games, compliance with first-order stochastic dominance, ability to plan ahead, and gender. We do find some systematic relationships. A subject’s compliance with first-order stochastic dominance as well as, possibly, patience, gender, and altruism have some systematic effects on her behavior in repeated games. At the level of a pair of subjects who are playing a repeated game, each subject’s gender as well as, possibly, patience and ability to choose an available dominant strategy in a one-shot matrix game systematically affect the frequency of the cooperate–cooperate outcome. However, overall, the number of systematic relationships is surprisingly small.     

Detecting motives for cooperation in public goods experiments

This study clarifies the types of motives that are important as a source of cooperation in a linear public goods experiment. Our experimental design separates contributions into those due to confusion, one-shot motives (which includes altruism, warm-glow, inequality aversion, and conditional cooperation), and multi-round motives (which includes a strategic motive under incomplete information, a failure of backward induction, and reciprocity). The experiment reveals that multi-round motives plays an important role in driving cooperative behavior. Confusion and one-shot motives play a minor role.     

Cooperation without Reputation: Experimental Evidence from Prisoner's Dilemma Games

This paper investigates cooperative play in prisoner's dilemma games by designing an experiment to evaluate the ability of two leading theories of observed cooperation: reputation building and altruism. We analyze both one-shot and finitely repeated games to gauge the importance of these theories. We conclude that neither altruism nor reputation building alone can explain our observations. The reputation model is inconsistent with play in both one-shots and finitely repeated games while the model with altruism is unable to explain observed play in the finitely repeated games.Journal of Economic LiteratureClassification Numbers: C72, C92.     

Altruism and Spite in a Selfish Gene Model of Endogenous Preferences

Economists and biologists have long grappled with the apparent contradiction of altruism in a naturally-selected world. Standard economic models are built upon an assumption of material self-interest where agents maximize individual outcomes without regard for the effects on others. This paper begins with a brief discussion of the evidence that human behavior deviates from the economic assumption. With the goal of more accurately describing human nature, the interpersonal components of preferences are derived in a genetic model. This model predicts a variety of behaviors that are considered paradoxical within the standard economic framework. The optimal attitude towards others is parameterized by the genetic relationship between individuals and by the population size. For interactions between ‘average’ individuals, the standard economic assumption is the limiting case of the genetic model as the population becomes arbitrarily large. This revised version was published online in August 2006 with corrections to the Cover Date.