OPTIONS AND EFFICIENCY IN MULTIDATE SECURITY MARKETS

This paper extends the work of Ross (1976; Q. J. Econ. (90)1, 75–89) to multidate security markets. First, we show that if a primitive security separates states at the terminal date, then there exist multiperiod European options on that security generating dynamically complete markets. Second, we show that if a primitive security conditionally separates states at the terminal date, then there exist multiperiod European options on that security generating generically dynamically complete markets provided that certain conditions hold. Third, we show that there are economies for which the minimum number of multiperiod European options on a primitive security generating generically dynamically complete markets is relatively large. Finally, we show that in these economies, a relatively small number of multiperiod European options on possibly different portfolio strategies of primitive securities generates generically dynamically complete markets.     

Boundedly complete families which are not complete

Summary Completeness of a family of probability distributions implies its bounded completeness but not conversely. An example of a family which is boundedly complete but not complete was presented by Lehmann and Scheffe [5]. This appears to be the only such example quoted in the statistical literature. The purpose of this note is to provide further examples of this type. It is shown that any given family of power series distributions can be used to construct a class containing infinitely many boundedly complete, but not complete, families. Furthermore, it is shown that the family of continuous distributions , is boundedly complete, but not complete, whereU denotes the uniform distribution on [a, b] and {P _ϑ,ϑ ∈ IR}, is a translation family generated by a distributionP ₀ with mean value zero, which is continuous with respect to the Lebesgue measure.     

试论传统文化与现代科学的同构兼容

探讨了传统文化与现代科学之间的同构兼容关系，认为在冲突中发展的人类文化是一个有机成长的开放系统，而科学的发展也是渐进积累和不断革命的统一，文化与科学的兼容特征决定了传统文化与现代科学完全可能谋求一种良性的同构兼容关系，     

基于博弈理念构建和谐税收制度的基本思路

本文阐述了和谐税收制度对建设和谐社会的重要性,指出和谐的税收制度应是一种纳什均衡的制度.运用博弈理念,从税种结构博弈均衡、税收负担博弈均衡、税收征管博弈均衡及稽查监督博弈均衡四个方面给出构建和谐税收制度的基本思路.     

国有土地使用权招拍挂出让制度的绩效分析

从制度变迁角度讨论了制度与经济绩效的关系,认为国有土地使用权招拍挂出让制度的建立是一种强制性的制度变迁,并从制度兼容性角度对该项制度的绩效进行了分析,最后在制度完善方面提出了相应的建议。     

政府责任与中国乳品消费的扩展

从政府责任的角度，提出“完全信息”假设强合理性的观点，从而恢复了新古典经济学关于“完全信息”假设合理性的本来地位。在此基础上，提出政府监管对乳品质量相对完全信息的提供以及对乳品消费拓展具有重要作用。并就政府乳品安全监管机制的选择以及政府在乳品消费习惯形成中的责任进行了探讨。     

基于网络外部性的价值模块整合与兼容性选择

本文分析了价值模块的网络外部性特征，并基于网络外部性研究了价值模块整合过程中的兼容性选择和价格竞争行为。研究结果表明：当由进入厂商选择兼容度时，兼容性越高进入厂商的市场份额越大，并能够获得更高的市场价格；当由在位厂商选择兼容度时，兼容度增加将减少消费者的转移成本，使更多的模块需求商转向购买进入厂商的产品，减少了在位厂商的市场份额；当转移成本的兼容性敏感系数较低时，在位模块供应商能够获得更高的价格，而当转移成本对兼容性很敏感时，较高的兼容度将迫使在位模块供应商降低价格。价值模块的网络外部性加剧了模块供应商之间的竞争，进一步促进了价值模块整合和产业融合的过程。     

再思社会科学方法论的形式主义与实质主义之争——以经济学的新进展为例

笔者从社会科学方法论中的形式主义与实质主义之争这一古老论题出发,阐明了经济学中的形式主义思想在最近半个世纪的发展是建立细节完全刻画的"全模型",并指出其背后的理念不在于建立普遍规律,而在于形成可以用以启发人们理解经验世界的辅助性认知手段。在澄清全模型方法认识论价值的同时,本文也指出其应用重点不在于形成理想化与意识形态化的叙事,而在于针对局域的经验事实,建立具有确定经验限定意涵的模型化推论,以阐明经验事实背后不易被单纯质性研究阐发的机制。当代经济学方法论显示的这一发展,可以被称为"形式主义经济学的实质主义化",对这一趋势的把握有助于揭示主流经济学独特的认识论价值。     

Truthful germs are contagious: A local-to-global characterization of truthfulness

We study the question of which social choice functions from an abstract type space to a set of outcomes are truthful, i.e., implementable by truthful mechanisms, when utilities are quasi-linear. For convex domains, our main theorem characterizes truthful social choice functions as those satisfying two properties: local weak monotonicity and vortex-freeness. The first of these constrains the function values at any two sufficiently proximal points, while the second asserts that its line integrals around sufficiently small triangular loops must vanish.The characterization implies a local-to-global principle that allows one to deduce truthfulness of a function from its behavior on arbitrarily small neighborhoods of each point. Other consequences include a simple alternate derivation of the Saks–Yu Theorem that weak monotonicity characterizes truthfulness of functions having a convex domain and finite range, and a sufficient condition for constructing truthful functions by “stitching together” truthful subfunctions on different subsets of the domain.