Stochastic durations,the convexity effect,and the impact of interest rate changes

This article shows that the equilibrium models of bond pricing do not preclude arbitrage opportunities caused by convexity. Consequently, stochastic durations derived from these models are limited in their ability to act as interest rate risk measures. The research of the present article makes use of an intertemporal utility maximization framework to determine the conditions under which duration is an adequate interest rate risk measure. Additionally, we show that zero coupon bonds satisfy those equilibrium conditions, whereas coupon bonds or bond portfolios do not as a result of the convexity effect. The results are supported by empirical evidence, which confirms the influence of convexity on the deviation of coupon bond returns from equilibrium.     

3MZ2325CNC轴承外圈滚道数控磨床故障处理

以3MZ2325CNC圆锥滚子轴承外圈滚道凸度数控磨床为例,描述了西门子802dsl数控系统出现故障的处理方法、步骤和注意事项。     

Risk forecasting models and optimal portfolio selection

This study analyses, from an investor's perspective, the performance of several risk forecasting models in obtaining optimal portfolios. The plausibility of the homoscedastic hypothesis implied in the classical Markowitz model is dicussed and more general models which take into account assymetry and time varying risk are analysed. Specifically, it studies whether ARCH-type based models obtain portfolios whose risk-adjusted returns exceed those of the classical Markowitz model. The same analysis is performed with models based on the Lower Partial Moment (LPM) which take into account the assymetry in the distribution of returns. The results suggest that none of the models achieve a clearly superior average performance. It is also found that models based on semivariance perform as well as those based on the variance, but not better than, even if the evaluation criterion is based on the Reward-to-Semivariance ratio. When attention turns to the analysis of worst case performance, the results are clearly different. Models which employ LPM with a high degree of risk aversion (n>2) as the risk measure are consistently superior to those which employ a symmetric measure, either homoscedastic or heteroscedastic.     

Equilibria in a large production economy with an infinite dimensional commodity space and price dependent preferences

We prove the existence of a competitive equilibrium in a production economy with infinitely many commodities and a measure space of agents whose preferences are price dependent. We employ a saturated measure space for the set of agents and apply recent results for an infinite dimensional separable Banach space such as Lyapunov’s convexity theorem and an exact Fatou’s lemma to obtain the result.     

Range convexity and ambiguity averse preferences

We show that range convexity of beliefs, a `technical' condition that appears naturally in axiomatizations of preferences in a Savage-like framework, imposes some unexpected restrictions when modelling ambiguity averse preferences. That is, when it is added to a mild condition, range convexity makes the preferences collapse to subjective expected utility as soon as they satisfy structural conditions that are typically used to characterize ambiguity aversion. Received: February 25, 2000; revised version: April 17, 2000     

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.     

久期和资产负债管理中的利率免疫策略

文章对目前广泛应用的利率风险度量方法包括久期、修正久期和凸度进行了深入分析。运用久期—凸度方法,研究了资产负债管理的利率免疫策略。针对利率变动的结构因素(即各种金融资产的利率同时上升或下降相同的数额)的局限,通过建立数学模型,对此方法进行了一定的改进,从而为人们在资产负债管理中实行利率免疫策略提供一种参考。     

含期权债券利率风险的衡量

久期(Duration)和凸度(Convexity)是度量普通债券利率风险的常用指标。含权债券中内嵌的期权会改变债券价格变动和利率变动的关系,使债券面临更大的利率风险,但常用的久期和凸度无法体现这一影响。实际久期和实际凸度可以弥补这一缺陷,是衡量含权债券利率风险的有效指标。对国家开发银行发行的可赎回债券和可回售债券的模拟和实证分析表明,由于内嵌了期权,在有些情况下实际凸度解释了大部分的利率风险,因此建议在投资中使用实际久期和实际凸度来衡量含权债券的利率风险,而且在利率比较高或比较低时不可忽略实际凸度对利率风险的解释作用。     

On a class of loans with a systematic amortisation schedule

Abstract

In this paper we show that a single set of formulas will characterise a wide range of standard loans. This makes it possible to describe these loans in a compact manner and facilitates the design of computer programs calculating their characteristics. The characterisation includes the entire amortisation schedule before and after tax and the duration and convexity measures.     

Technical Efficiency in the Angolan Banking Sector with the B‐convexity Model

This paper analyses technical efficiency in Angolan banks from 2005 to 2010 with an innovative production frontier model, the model. The intermediate approach is adopted. It is observed that the efficiency increases over the observation period, according to the international experience, market share and local markets. Policy implications indicate that competition and governance should be promoted in order to increase efficiency.