【作者】 代利；

【导师】 唐晓嘉；

【作者基本信息】 西南大学 ， 逻辑学， 2012， 博士

【摘要】 如何将个体理性聚合为群体理性是社会理性认知研究面临的主要难题,同时也是经济学、哲学、政治学、法学及计算机科学等多学科交叉研究的热点问题之一。美国著名经济学家阿罗(Kenneth Arrow)([6])教授以公理化的方法刻画了个体理性偏好与群体理性偏好,在此基础上证明将理性个体偏好聚合为理性群体偏好的不可能性。如何理解刻画这种不可能性以期化解,寻求合理的群体理性聚合方法成为相关研究必须突破的理论瓶颈,近年出现的判断聚合研究为这一问题的突破提供了新思路。偏好聚合与判断聚合是群体理性聚合研究的两个基本模型,偏好聚合在社会选择理论中已得到深入研究,社会选择理论所关心的主要问题是：一个群体是如何能够将其中个体的偏好聚合起来而作出一个群体决策的。近年出现的判断聚合与偏好聚合相比有诸多理论优势,逐渐成为群体理性聚合研究的中心。判断聚合从逻辑的视角更一般地研究聚合,探讨如何将多个一致的逻辑公式集聚合成一个一致的逻辑公式集。已有研究([21,72]等)表明：判断聚合与偏好聚合之间有着密切联系,判断聚合中也存在与偏好聚合中的阿罗定理等类似的不可能性结论。偏好聚合与判断聚合中的不可能性结论从不同层面揭示了在满足一些通常合理的条件下,将个体理性聚合为群体理性的不可能性。近年来,现代逻辑理论在知识更新、信念修正以及偏好升级等问题的研究中得到了广泛应用与快速发展,从而为探究群体理性聚合难题提供了有效的理论分析工具。本文运用现代逻辑工具探讨判断聚合与偏好聚合之间的密切联系,论证判断聚合模型较偏好聚合模型在群体理性聚合研究中的理论优势,进而基于判断聚合模型对群体理性聚合问题进行深入研究,探寻群体理性聚合难题切实可行的化解方案,以期为现实中群体决策方案的制定奠定坚实的理论基础,从而进一步推动社会理性认知的形式化研究。本文首先细致梳理了群体理性聚合研究的两个基本模型——偏好聚合与判断聚合,引出了群体理性聚合中的一些难题。接着,运用现代逻辑工具对群体理性聚合问题进行形式分析与刻画,从逻辑的视角探讨偏好聚合与判断聚合之间的密切联系,论证偏好聚合是判断聚合的一个特例。其中重点分析了一个判断聚合的模态逻辑JAL。虽然JAL的语形、语义都很简单,但它却具有很强的表达力,可以直接运用JAL对判断聚合规则进行刻画。利用一阶逻辑的语言基于JAL可以构建一个偏好聚合的逻辑系统JAL(LK),从而可将偏好聚合转化为判断聚合来处理,突显了判断聚合模型的一般性,同时也进一步论证了判断聚合模型在群体理性聚合研究中的理论优势。然后,基于对一个判断聚合不可能性定理的严格证明,提出了群体理性聚合难题的诸多化解途径如限制判断聚合规则的定义域、放宽判断聚合规则的输出条件、放弃独立性等,对于每种化解途径都给出了切实可行的化解方案,从而突显了本研究的重要理论意义与广泛的实际应用价值。最后,我们对本文的研究成果进行了总结与讨论,并明确了下一步研究的方向。更多还原

【Abstract】 How to aggregate individual rationality into collective rationality is the main problem faced by the cognitive study of social rationality, it is also one of the hot interdisciplinary questions among economics, philosophy, politics, law and computer science etc. The famous American economist Professor Kenneth Arrow ([6]) used the axiomatic method depicting individual rationality and collective rationality, and proved the impossibility of aggregating the rational individual preference into the rational collective preference. It becomes an important problem in many studying areas that how to understand the impossibility and to dissolve it for finding reasonable collective rationality aggregating methods,judgment aggregation provided a-new idea for the breakthrough of the problem. Preference aggregation and judgment aggregation are the two basic models for studying collective rationality aggregation.Preference aggregation has been deeply studied in the social choice theory. In social choice theory, it is the main question how to make a collective decision based on the preference of individuals in the group.Judgment aggregation which emerge recently has many theoretical advantages compared with preference aggregation. Judgment aggregation becomes the center of studying collective rationality aggregation gradually. From the perspective of logic, judgment aggregation consider how to aggregate many logical consistent formula into one logical consistent formulue.Now the existing research results([21,72]etc.) show that:there has been close connection between judgment aggregation and preference aggregation, the similar impossibility conclusions like Arrow Therem in the area of preference aggregation existed also in the area of judgment aggregation.The impossibility conclusions in the areas of preference aggregation and judgment aggregation revealed the imsossibility to aggregate individual rationality into collective rationality under some reasonable conditions. Recently modern logic has been used widely and developed rapidly in the areas of studying knowledge update,belief revision and preference upgrade etc., then the modern logic becomes the efficient theoretic tool to resolve the problem of aggregating collective rationality. Using the modern logic tools,we analyzed the close connection between judgment aggregation and preference aggregation,then proved the generality of judgement aggregation model compared with preference aggregation.Based on the judgment aggregation model,we study the collective rationality aggregation problem deeply,so as to explore feasible escape routes for it.This research would lay solid theoretical foundation for making collective decision schemes,thus further promote the formal study of social collective cognition.Firstly, this paper combed carefully the preference aggregation model and the judgment aggregation model which are the two basic models for studying collective rationality aggregation and drawed forth the difficult problems of collective rationality aggregation. Then,we used the modern logic tools to analyze and depict the problems of the collective rationality aggregation,discussed the close connection between judgment aggregation and preference aggregation from the logic prespective and illustrated that preference aggregation is a special case of judgment aggregation. Of which we analyzed mainly a judgment aggregation modal logic JAL.The syntax of JAL language is very simple,and so is its semantics.Having very powerful expression, the languag of JAL can be interpreted directly by the judgment aggregation rules.Based on JAL,we constructed a preference aggregation logic system JAL(hK) using the language of the first-order logic.Thus the preference aggregation questions could be converted into the judgment aggregation questions to be handled,so that the generality of the judgment aggregation model is highlighted and the theoretical advantages of the judgment aggregation model in analyzing the collective rationality aggregation is illustrated.And then, on the basis of a stict proof for a judgment aggregation impossibility conclusion,we put forward many ways for resolving the problems of the collective rationality aggregation,such as limitting the input of the judgment aggregation rules,loosening the output conditions of the judgment aggregation rules,abandoning the independence etc..Putting forward feasible schemes for every resolving way, we highlight the important theoretical significance and extensive practical application value of our research.Finally,we summarized and discussed the results of this paper and ascertain our future research.更多还原