Nash-equilibria in a heterogeneous oligopoly with fuzzy information

We consider a model of an oligopolistic market with heterogeneous firms and products where neither the cost nor the demand functions are common knowledge. Instead, each firm only has some vague ideas about the price strategies adopted by its competitors which is modelled by a fuzzy set. In analogy to the notion of an "equilibrium of actions and beliefs" we define and characterize a generalized Nash-equilibrium and show its existence under general conditions. Furthermore, the impact of the fuzzy information on the equilibrium outcome is analyzed by means of a comparative static analysis within a particular model framework.Received: 28 May 2002, Accepted: 25 December 2002, JEL Classification: D43, D80, L13We wish to thank Bernhard F. Arnold, the editor Murat Sertel , and two anonymous referees for helpful comments. Of course, we are responsible for all remaining errors.     

A note on the determination of A-optimal type block designs under fixed and mixed effects models

In this paper, we consider the problem of estimating a selected set of contrasts between v treatments using a block design consisting of b blocks of size k. Traditionally, the construction of A-optimal block designs for such situations has been carried out assuming a fixed effects model. In this paper, we show that A-optimal designs constructed under a fixed effects model are robust in the sense that these designs have maximal minimal efficiency when considered among all available designs and under all possible mixed effects models. AMS 1991 subject classifications: Primary 62K05; Secondary 62K10     

Duration dependence testing for speculative bubbles

Prior research has employed a number of methods to test for speculative bubbles in asset prices, including a method based on the concept of duration dependence. This study explores whether duration dependence tests for speculative bubbles are sensitive to specification decisions. Our results question the efficacy of using measures of duration dependence to test for speculative bubbles. In particular, we find that evidence of duration dependence is sensitive to the method of correcting for discrete observation of continuous duration, the use of value-weighted versus equally weighted portfolios, and the use of monthly versus weekly runs of abnormal returns. (JEL C41, G12)     

智能计算机辅助教学系统中建构新型教学模式

在分析了当前智能计算机辅助教学系统中存在的各种教学模式的基础上 ,提出了“双主”教学模式 ,即强调同时发挥学生的主体作用和教师的主导作用 ,并详细论述了建立“双主”教学模式的必要性和可行性。     

神府—东胜矿区沙漠化趋势预测与防治措施

神府－东胜矿区在特定的自然地质环境和人为因素的影响下，土地沙漠化呈不断扩展的演化趋势。矿区大规模的开发建设，更加速了沙漠化进展。本文利用典型地段的沙漠化发展速率，依据矿区总体设计规模，对矿区自然沙漠化趋势和开矿新增沙漠化土地面积进行了定量预测，并提出了相应的防治措施。     

论新一轮税制改革

始于1994年的我国现行税收制度,以其前所未有的统一、公平、规范稳健运行整整十年了。然而,在市场经济纵深发展、加入世贸组织等全新背景之下,严格审视现行税制,会发现仍存在许多新的问题。启动新一轮税制改革的必要性和重要性,已为包括企业界、理论界和政府部门在内的方方面面所熟知,甚至在社会上形成了强烈企盼。所以,如何认识现行税制存在的问题,如何按国际通行规则去调整、改革、完善之,具有十分重要的现实意义,有必要对此加以系统的研究。     

集合列的上(下)极限及其应用

从集合列的定义出发,系统总结并讨论了集合列的上(下)极限的一般性质。分别在广义实值函数空间和一般模糊测度空间上,利用集合列的上(下)极限定义和性质,研究了广义实值函数和一般模糊测度的表示和应用问题。     

中国对东盟纺织业投资的经济效应分析

中国对东盟纺织服装业的直接投资近年来发展很快。本文从中国对东盟纺织业加强投资的原因分析入手,提出了中国对越南、柬埔寨、印尼、泰国的纺织业投资的路径选择,进而具体分析了投资带来的缓解双方同构性出口竞争压力、提高双方纺织品贸易互补性、促进中国纺织产业结构升级的经济效应。在经济效应分析的基础上．指出中国加强和优化对东盟国家纺织业投资有助于提高中国纺织业整体的核心竞争力。     

基于递归对角神经网络自适应均衡算法的研究

阐述了神经网络自适应均衡算法的基本原理,提出了一种基于递归对角神经网络的自适应均衡算法,推导了算法的迭代公式,进行了计算机仿真。结果表明,随着传输信号信噪比的增加,稳态剩余误差减小,误码率降低。     

增值税改革刍议

增值税是我国目前流转税的一大税种，是我国的财政收入的重要来源和国家宏观调控政策的重要手段。本根据现今国际国内形势的发展，提出增值税在现阶段应该改进的一些方面，如税收链条不够完整、小规模纳税人税率设计有待商榷等等，以期完善增值税。