The representation of American options prices under stochastic volatility and jump-diffusion dynamics

This paper considers the problem of pricing American options when the dynamics of the underlying are driven by both stochastic volatility following a square-root process as used by Heston [Rev. Financial Stud., 1993, 6, 327–343], and by a Poisson jump process as introduced by Merton [J. Financial Econ., 1976, 3, 125–144]. Probability arguments are invoked to find a representation of the solution in terms of expectations over the joint distribution of the underlying process. A combination of Fourier transform in the log stock price and Laplace transform in the volatility is then applied to find the transition probability density function of the underlying process. It turns out that the price is given by an integral dependent upon the early exercise surface, for which a corresponding integral equation is obtained. The solution generalizes in an intuitive way the structure of the solution to the corresponding European option pricing problem obtained by Scott [Math. Finance, 1997, 7(4), 413–426], but here in the case of a call option and constant interest rates.     

Static hedging and pricing American knock-in put options

This paper extends the static hedging portfolio (SHP) approach of  and  to price and hedge American knock-in put options under the Black–Scholes model and the constant elasticity of variance (CEV) model. We use standard European calls (puts) to construct the SHPs for American up-and-in (down-and-in) puts. We also use theta-matching condition to improve the performance of the SHP approach. Numerical results indicate that the hedging effectiveness of a bi-monthly SHP is far less risky than that of a delta-hedging portfolio with daily rebalance. The numerical accuracy of the proposed method is comparable to the trinomial tree methods of  and . Furthermore, the recalculation time (the term is explained in Section 1) of the option prices is much easier and quicker than the tree method when the stock price and/or time to maturity are changed.     

The link between intraday signals and call warrant mispricing

This study proposes a linkage between intraday variables (signal amounts and signal duration) and the mispricing of Taiwan call warrant prices, based on the lower boundary condition of Merton [1973. Theory of rational option pricing. Bell Journal of Economics and Management Science, 4(1), 141–183] as modified by Galai [1978. Empirical tests of boundary conditions for CBOE options. Journal of Financial Economics, 9(2), 321–346]. Trading mispriced call warrants associated with a riskless hedging strategy over the period January 2004–December 2005 on average produces abnormal profits after taking into account transaction costs, as indicative of an inefficient market.     

Boundary spanner turnover in professional services: Exploring the outcomes of client retention strategies

Abstract

Studies suggest that the termination of the interpersonal relationship between boundary spanners at buyer and seller firms can have a damaging effect on the inter organisational relationship. Few studies have addressed this issue in detail, but those that do, advise supplier firms to implement strategies such as service teams and boundary spanner rotation to lessen the negative effects of boundary spanner turnover. By creating multiple bonds between the two firms, dispersing client-specific knowledge widely throughout the supplier firm, and preventing the development of a close bond between buyer and seller boundary spanners, individual interpersonal relationships become less important. However, a review of relationship literature on trust, commitment, social bonds, and knowledge suggests the potential for negative outcomes from the implementation of the strategies. Using case studies and one-to-one interviews with design buyers and their agencies, this paper explores the outcomes of the two strategies, and the contexts in which these outcomes occur. Adopting a critical realist approach, findings are presented in the form of context–mechanism–outcome models. Agency size, agency culture, client experience, and boundary-spanner autonomy are amongst the contexts that influence the outcome of strategy implementation.     

An ecological economic simulation model for assessing fire and grazing management effects on mesquite rangelands in Texas

In the southern Great Plains of North America, fire exclusion has contributed to many rangelands converting from native grassland to woody shrublands dominated by mesquite (Prosopis glandulosa Torr.) and cactus (Opuntia spp.), threatening ecosystem health and human livelihoods in the region. Prescribed fire is the least expensive method of treating mesquite and other undesirable plants, but its role is as a maintenance treatment to prolong the life of more expensive brush control treatments. Using a simulation model of a hypothetical 1000 ha ranch, we evaluate the biological and economic implications of management scenarios involving the regular application of summer fire to reduce mesquite and cactus over a 30-year time period. We compared the model output with experimental data to corroborate model output before evaluating various management scenarios over a range of stocking rates. Scenarios included (a) varying initial range condition, (b) different frequencies of summer burning, and (c) different initial amounts of mesquite brush. Model simulations corroborated field data sufficiently well to give confidence in the output of the model. In our simulations the option of not treating to reduce brush and cactus had a major negative impact on range condition, secondary productivity and profitability. In contrast, all simulated fire treatments improved range condition, productivity and profitability except when initial range condition was poor. Initial range condition and stocking rate were the major factors affecting both productivity and profitability. Compared to other factors over which managers have short-term control, frequency of burning and the initial amount of mesquite cover, had a relatively minor impact. Simulations indicated that the highest level of profit consistent with maintaining or improving range condition was attained when individual animal production was 92-95% that of the maximum production per animal, a situation invariably associated with relatively low stocking rates.     

都市区空间范围的划分方法

都市区已成为中国城市化快速发展的重要载体,但其地域空间范围划分标准尚不明晰,从而影响到空间规划的科学性和空间管治的可操作性。在对国内外都市区定义及划分方法的简要评述基础上,考虑到我国都市区发展所处的阶段,提出产业经济空间和人口经济空间两种划分方法。研究认为由于城市产业经济活动的多样性及其产业活动影响范围的差异性会导致产业经济空间的划分方法难以具体实施,推荐以核心城市人口经济活动的空间范围来划分都市区。在此讨论基础上,对全国尺度上的大都市区空间范围进行了大致匡算和划分,目前全国共有30个大都市区;并以北京市作为案例点,利用GIS技术,考虑道路交通系统,更为具体详细地对北京市都市区范围进行了界定,都市区地域空间形态表现为明显的锯齿状。     

城市增长边界的理论探讨与应用

城市增长边界(UGB)是当前美国等西方国家在城市可持续发展及空间扩张管理等方面研究的热点之一。文章旨在诠释UGB的内涵、特征以及效能的基础上,对国内的相关研究进行了回顾与评价,并对中国设定UGB的必要性进行了阐述。结果表明:设立城市发展边界(UGB)对于中国的城市空间扩张管理有着十分重要的指导意义,但UGB管理模式并不能够简单地"复制"到中国,需要从正确定位、划定方法、整合管理及弹性控制等方面进行创新。     

企业集团边界的演变趋势研究

提出母子公司体制下的企业集团,其基于控制权的治理边界,超越了企业法人边界,使得其边界非平面性,而是三维立体的边界。还进一步从动机、有效范围、演变趋势等方面对企业集团三维边界作了分析,提出现实生活中企业集团整合边界范围帕累托最优是比较困难的,尤其是大型国有企业集团在战略重组中往往只能在不优的整体边界范围内创造局部有效的边界范围。最后,运用所提出的理论观点对我国企业集团成长中的规模、结构、管控等问题进行了解释。     

Classical biased technical change approach and its relevance to reality

The purpose of this article is to evaluate empirically the classical viability condition for East Asia, Latin America, Sub‐Saharan Africa 1980–1995, and advanced countries 1950–1992. The viability condition is proposed by Foley and Michl (1999 Foley, D.K. and Michl, T.R. 1999. Growth and Distribution, Cambridge, MA: Harvard University Press.  [Google Scholar]), and is used for judging empirically which approach is more valid, the classical biased technical change approach or neoclassical production function approach. Our results acknowledge the predominance of the former, which is Foley‐Michl’s contention. However, there remains a disputable interpretation as to the case of a declining labour productivity, which is broadly seen in Latin America and Sub‐Saharan Africa during the period considered.     

基于核心能力半径的企业规模边界

企业规模边界的扩张是企业实现增长的一种重要方式,实质是企业能力半径的构建和强化。以核心能力为视角,分析决定企业核心能力半径的因素发现,在不同核心能力半径下,企业规模边界的变动存在规律性变化,企业的能力半径决定了企业规模边界的上限,而核心能力半径决定了企业规模边界的下限。