A note on the existence of unique equivalent martingale measures in a Markovian setting

Simple sufficient conditions for the existence of a unique equivalent martingale measure are provided. Furthermore, these conditions give us a handle on situations where an equivalent martingale measure cannot exist. The existence of a unique equivalent martingale measure is of relevance to problems in mathematical finance. Two examples of models for which the question of existence was unresolved are studied. By means of our results existence of a unique equivalent measure up to an explosion time is proved.     

试论生态林业系统的时空观

生态林业系统具有时间、空间两个序列的开发前景。长周期,大跨度的生态林业生产可以分解为复合的短周期方式,使生态意识与经济效益有机结合。空间组合的多层次立体开发有效地利用了光、热、水、土资源,并获得最大生物量;地域组合着眼宏观,注重研究大型骨干及网络性生态工程问题。     

Working-time reduction and employment: experiences in Europe and economic policy recommendations

The paper seeks to evaluate the evidence on the employment effectsof the collective working-time reductions in Europe over thepast 20 years. While theoretical analyses produce contradictoryassessments, most empirical studies show positive employmenteffects but take insufficient account of these conditions underwhich the reductions in working time were implemented. Theseconditions for the success of collective working-time reductionsinclude an active training policy designed to minimise skillshortages in the labour market, the modernisation of work organisation,wage increases in conjunction with productivity gains and amore equal income distribution.     

供应链构建的机制分析

介绍了供应链的概念，交易成本经济学的基本理论，并把二者结合从经济学的角度分析了供应链构建的经济学机理，为供应链理论的发展提供了一个新的研究方向。     

对合肥市房地产业现状的几点看法

特定社会的分配关系总是由该社会的生产资料所有制关系和劳动力所有制关系决定的。社会主义初级阶段不成熟、不发达的生产资料公有制和劳动者劳动力发展不充分、不平衡决定了在分配上只能实行按劳分配和按要素分配相结合的制度。这是马克思主义分配理论的重大突破和巨大发展 ,     

浅谈会计信息供求的特殊性

会计信息作为一种特殊的商品和普通商品一样,也存在供给方和需求方,会计信息要实现其价值和使用价值,必须在供求双方之间进行交易,因此,会计信息也遵循一般商品的交换规律。但是,由于会计信息既具有公共物品的属性又具有私人物品的属性,所以在供求交换的过程中,又具有自己的特殊性。而正是这种特殊性,使得会计信息市场处于混乱状态,因此,探讨会计信息供求的特殊性具有重要的现实意义。     

LABOUR SUPPLY ESTIMATION AND PUBLIC POLICY

Abstract. Economists devote considerable energies towards refining their econometric techniques to overcome difficulties connected with conducting empirical research. Despite advances in technique. it is not clear whether further refinement in this direction is worthwhile for policy purposes. It may be that no further amount of statistical adjustment of inadequate data will increase understanding, and that better data is simply necessary to add to our knowledge. But rarely is sufficient credit paid to new forms of data. In short, econometric technique is emphasized to the neglect of data innovation, as if new data were merely lying about waiting for an ingenious suggestion for use. This paper surveys advances of the last twenty five years in estimating labour supply for policy purposes with a view towards appreciating the relative contribution of both improvements in econometric technique as well as developments of new data.
After briefly detailing the key parameters which economists have sought to estimate, we describe the early 'first generation' research (circa 1970), which is plagued by problems of unobservable variables, measurement errors, truncation and selectivity bias, and non linear budget constraints. 'Second generation' research constitute attempts to resolve one or more of these difficulties, and the respective contribution of econometric technique and new data is acknowledged and assessed, including the contribution of data generated by large scale social experiments in which participants are randomly assigned to different guaranteed income plans and their labour supply behaviour measured.     

国际贸易中的技术性壁垒及我国对策

二十一世纪是全球经济一体化的知识时代 ,科学的巨大变革已经渗透于人类社会的方方面面 ,而国际贸易中的技术性壁垒则体现了贸易保护主义与科技相结合的作用。并且 ,这种非关税壁垒形式以其正义的外衣、巨大的影响力和借助科技的快速发展越来越成为国际贸易中不可忽视的保护手段。中国作为世界贸易组织的新成员更应在这方面进行研究 ,并制定相应的战略。     

拖拉机总装流水线的时间平衡

本文联系拖拉机总装配的实际,阐述了装配线时间平衡的做法及其所可取得的显著的经济效益。