产品市场竞争下两职合一对公司绩效的影响

运用2006—2013年中国A股上市公司的数据,考察了产品市场竞争下董事长与总经理两职合一对公司绩效的影响及其作用机理。结果表明:随着产品市场竞争的加剧,两职合一对公司绩效有显著的正向影响;产品市场竞争通过约束管理层的行为减少委托代理问题的发生,且两职合一的信息优势和沟通效率促进了公司业绩的提升。因此,在复杂多变的外部环境中董事长与总经理两职合一更有利于公司经营。     

DO ARBITRAGE‐FREE PRICES COME FROM UTILITY MAXIMIZATION?

In this paper we ask whether, given a stock market and an illiquid derivative, there exists arbitrage‐free prices at which a utility‐maximizing agent would always want to buy the derivative, irrespectively of his own initial endowment of derivatives and cash. We prove that this is false for any given investor if one considers all initial endowments with finite utility, and that it can instead be true if one restricts to the endowments in the interior. We show, however, how the endowments on the boundary can give rise to very odd phenomena; for example, an investor with such an endowment would choose not to trade in the derivative even at prices arbitrarily close to some arbitrage price.     

Consistent loss prediction for a portfolio and its subportfolios

In the present paper, we consider a portfolio of risks consisting of two subportfolios, and we study the problem of whether or not the predictors based on the subportfolios are consistent with those based on the full portfolio. We study this aggregation problem for both the chain-ladder method and the additive method (or incremental loss ratio method). In the case of the chain-ladder method we extend results of Ajne and Klemmt, using the duality of the chain-ladder method applied to incremental losses; we also give a short proof for this duality, which was first observed by Barnett, Zehnwirth & Dubossarky. In the case of the additive method the aggregation problem has not been studied before and its solution is surprisingly simple.     

EQUITY CORRELATIONS IMPLIED BY INDEX OPTIONS: ESTIMATION AND MODEL UNCERTAINTY ANALYSIS

We propose a method for constructing an arbitrage‐free multiasset pricing model which is consistent with a set of observed single‐ and multiasset derivative prices. The pricing model is constructed as a random mixture of N reference models, where the distribution of mixture weights is obtained by solving a well‐posed convex optimization problem. Application of this method to equity and index options shows that, whereas multivariate diffusion models with constant correlation fail to match the prices of index and component options simultaneously, a jump‐diffusion model with a common jump component affecting all stocks enables to do so. Furthermore, we show that even within a parametric model class, there is a wide range of correlation patterns compatible with observed prices of index options. Our method allows, as a by product, to quantify this model uncertainty with no further computational effort and propose static hedging strategies for reducing the exposure of multiasset derivatives to model uncertainty.     

On the Consumer Value of Diversity: An Application to Italian Fish

This article investigates the consumer value of diversity both conceptually and empirically. It proposes a measure of diversity value based on a benefit function. It shows that the consumer value of diversity can arise from complementarity and/or convexity effects among consumer goods. The usefulness of the approach is illustrated by an application to fish in Italy. The investigation illustrates the role played by both convexity and complementarity in the valuation of diversity. The empirical evidence shows the importance of dynamics. It also documents how the value of diversity varies depending on the bundles considered.     

全球化进程中文化冲突的两重性

全球化所带来的文化冲突对文化的发展不仅起着积极的作用,也起着消极的作用.如果我们能对这些客观的作用加以正确认识和引导,就会化消极为积极,促进文化及整个人类社会的发展和繁荣.     

中国市场可转债宣告效应的实证研究

文章以我国目前在深沪两市交易的28只可转债为样本,用市场调整后的累积超额回报率来衡量发行可转债的宣告效应.通过对公告期内拟转换股票累积超额回报率的统计分析发现,公告期两天累积超额回报率CAR(-1,0)的平均值小于零,也就是说宣告发行可转债对市场有一定的负面影响,但比增发股票的负面影响要小.为研究累积超额回报率的影响因素和影响机制,以(-1,0)时间窗口内的累积超额回报率为因变量,以发行规模、发行期限、公司规模、公司成长性、公司财务杠杆为自变量建立起回归模型进行了实证研究,得出了几个较有意义的结论.     

我国物流园区二元结构与物流园区发展

通过分析物流园区二元结构的现状、成因.并基于发展园区的目的提出了解决当前我国物流园区二元结构矛盾的方案.即通过主管部门政策性引导。由自发性向规划性有计划的转移;通过市场竞争.逐步淘汰园区的自发性经营活动。     

浅析电磁学教学中思维定势的双重性

针对电磁学课程教学中的思维定势，运用教育心理学与物理思维论，分析了其产生原因和机制，阐述了其双重性，探寻了相应的教学对蓑、对经典物理教学模式的现代化建设具有实用价值。     

Randomized Stopping Times and American Option Pricing with Transaction Costs

In a general discrete-time market model with proportional transaction costs, we derive new expectation representations of the range of arbitrage-free prices of an arbitrary American option. The upper bound of this range is called the upper hedging price, and is the smallest initial wealth needed to construct a self-financing portfolio whose value dominates the option payoff at all times. A surprising feature of our upper hedging price representation is that it requires the use of randomized stopping times (Baxter and Chacon 1977), just as ordinary stopping times are needed in the absence of transaction costs. We also represent the upper hedging price as the optimum value of a variety of optimization problems. Additionally, we show a two-player game where at Nash equilibrium the value to both players is the upper hedging price, and one of the players must in general choose a mixture of stopping times. We derive similar representations for the lower hedging price as well. Our results make use of strong duality in linear programming.