有界灰数空间的完备性可分性与局部紧性

本文首先指出有界灰数对于四则运算不具备封闭性。证明了有界灰数所构成的空间(G(?),D)是可分的,局部紧的完备度量空间。     

On the use of measure-valued strategies in bond markets

We propose here a theory of cylindrical stochastic integration, recently developed by Mikulevicius and Rozovskii, as mathematical background to the theory of bond markets. In this theory, since there is a continuum of securities, it seems natural to define a portfolio as a measure on maturities. However, it turns out that this set of strategies is not complete, and the theory of cylindrical integration allows one to overcome this difficulty. Our approach generalizes the measure-valued strategies: this explains some known results, such as approximate completeness, but at the same time it also shows that either the optimal strategy is based on a finite number of bonds or it is not necessarily a measure-valued process.Received: November 2002, Mathematics Subject Classification: 60H05, 60G60, 90A09JEL Classification: G10, E43The first author gratefully acknowledges financial support from the CNR Strategic Project Modellizzazione matematica di fenomeni economici. We thank professors A. Bagchi, R. Douady and J. Zabczyk for helpful discussions. A special thanks goes to professors T. Björk, Y. Kabanov and W. Schachermayer for comments and suggestions which contributed to improve the final version of this paper.     

要素集聚、产权完整性与城乡收入差距

本文从要素集聚与产权完整性视角研究中国城乡收入差距,认为中国的市场化进程其实就是生产要素从农村地区向城市地区单向流动的过程,并且中国城市居民的产权是完整的,而农村居民的产权是不完整的。这种生产要素的集聚导致城乡交易成本、生产效率的差异,进而导致城乡收入差距;要素集聚还使得城市居民的资产增殖,而农村居民的资产无法增殖;城乡居民产权的完整性差异是生产要素向城市集聚的一个重要原因,通过要素集聚间接影响城乡收入差距;另外城乡居民产权的完整性差异还会直接导致城乡收入差距。本文通过2002—2011年省级面板数据对要素集聚与产权完整性对城乡收入差距的影响予以实证研究,并给出政策建议。     

契约型农产品营销渠道治理过程研究：收购商管理控制的中介作用

文章以渠道治理和管理控制理论为基础，从交易关系发展过程的视角，将管理控制作为渠道治理的过程机制，重点考察其在保障契约机制有效执行过程中的中介作用以及农户专有资产净投入对契约完备性与管理控制之间关系的调节影响。通过对来自参与订单农业的217份的农户调查数据进行分析发现：收购商的三种管理控制方式（结果控制、过程控制和能力控制）在契约完备性对农户绩效的提升过程中起到中介作用，过程控制也在契约完备性抑制农户投机行为的过程中起到中介作用。同时，研究证实了农户专有资产净投入高时，削弱了契约完备性对三种管理控制正向影响。     

商品空缺陈列对消费者选购决策的影响

营销实践和研究文献多强调饱满陈列的作用。假设空缺陈列在特定条件下也会产生积极的效果,商场环境、产品信息、购买卷入度、购买者个性特点是影响空缺陈列作用效果的重要变量。实验结果表明不知名产品的空缺陈列比饱满陈列效果好,但多个产品同时空缺陈列时销售量下降。     

Semi‐efficient valuations and put‐call parity

We propose an approach to the valuation of payoffs in general semimartingale models of financial markets where prices are nonnegative. Each asset price can hit 0; we only exclude that this ever happens simultaneously for all assets. We start from two simple, economically motivated axioms, namely, absence of arbitrage (in the sense of NUPBR) and absence of relative arbitrage among all buy‐and‐hold strategies (called static efficiency). A valuation process for a payoff is then called semi‐efficient consistent if the financial market enlarged by that process still satisfies this combination of properties. It turns out that this approach lies in the middle between the extremes of valuing by risk‐neutral expectation and valuing by absence of arbitrage alone. We show that this always yields put‐call parity, although put and call values themselves can be nonunique, even for complete markets. We provide general formulas for put and call values in complete markets and show that these are symmetric and that both contain three terms in general. We also show that our approach recovers all the put‐call parity respecting valuation formulas in the classic theory as special cases, and we explain when and how the different terms in the put and call valuation formulas disappear or simplify. Along the way, we also define and characterize completeness for general semimartingale financial markets and connect this to the classic theory.     

On the completeness of certain classes of two stage sampling strategies

Summary In this paper the problem of estimation of the population mean, for a finite two statge population, under the assumptions of non-informativeness of labels of distinguishable units has been studied. Completeness of certain classes of strategies, for estimating the population mean, under a two stage random permutation model, has been established.     

法律与行政环境对信托公司绩效的影响研究

以2006~2012年的中国信托公司为样本,采用法与金融学理论研究方法,研究信托公司所处的法律环境与行政环境对公司绩效的影响。结果表明,信托法律体系的完善、投资保护力度的提升及良好的地方法治环境对信托公司绩效具有显著促进作用,政府廉洁度的提升对信托公司绩效也有显著的正向影响。     

论我国金融配置效率的改进与企业债券市场的发展

本文利用金融学基础理论—市场完全性原理对我国金融体系资源配置低效率进行剖析,认为其根源在于市场的极度不完全,有限的金融工具对应日益扩大的风险空间,风险与收益严重不对称,金融风险不断积聚。因此应发展能够通过风险与收益的匹配进行资源有效配置的资本工具特别是企业债券,以降低我国经济运行中的潜在金融风险。针对我国区域经济不平衡的现实,可考虑通过建立区域债券交易中心来推动我国企业债券市场的发展。     

THE TWO FUNDAMENTAL THEOREMS OF ASSET PRICING FOR A CLASS OF CONTINUOUS‐TIME FINANCIAL MARKETS

The paper is concerned with the first and the second fundamental theorems of asset pricing in the case of nonexploding financial markets, in which the excess‐returns from risky securities represent continuous semimartingales with absolutely continuous predictable characteristics. For such markets, the notions of “arbitrage” and “completeness” are characterized as properties of the distribution law of the excess‐returns. It is shown that any form of arbitrage is tantamount to guaranteed arbitrage, which leads to a somewhat stronger version of the first fundamental theorem. New proofs of the first and the second fundamental theorems, which rely exclusively on methods from stochastic analysis, are established.