A MULTINOMIAL APPROXIMATION FOR AMERICAN OPTION PRICES IN LÉVY PROCESS MODELS

This paper gives a tree-based method for pricing American options in models where the stock price follows a general exponential Lévy process. A multinomial model for approximating the stock price process, which can be viewed as generalizing the binomial model of Cox, Ross, and Rubinstein (1979) for geometric Brownian motion, is developed. Under mild conditions, it is proved that the stock price process and the prices of American-type options on the stock, calculated from the multinomial model, converge to the corresponding prices under the continuous time Lévy process model. Explicit illustrations are given for the variance gamma model and the normal inverse Gaussian process when the option is an American put, but the procedure is applicable to a much wider class of derivatives including some path-dependent options. Our approach overcomes some practical difficulties that have previously been encountered when the Lévy process has infinite activity.     

用基变换方法求多项式的泰勒公式

通过分析多项式函数f(x)在不同点处的泰勒公式与线性空间基变换的联系,得到了多项式在同点处泰勒公式的一种求解方法。     

Modeling Disinterest and Dislike: A Bounded Bayesian Mixed Logit Model of the UK Market for GM Food

Mixed logit models represent a powerful discrete choice analytical model but require assumptions about the functional form of the parameter distributions. The use of unbounded distributions, such as the normal distribution, may be regarded as unsuitable where theory indicates that all are negatively affected by increases in an attribute, such as price. Bounded distributions such as the triangular and log-normal are unable to model the case where a section of the population is indifferent towards an attribute, while the remainder are negatively disposed toward it. Train and Sonnier’s bounded mixed logit model accommodates these features and is employed in this paper. A censored normal and Johnson’s S_b distribution are used to model preferences in the UK for food attributes, including price and GM technology. Bi-modal distributions are identified regarding GM food: some are unlikely to ever consume it, some are close to indifference and willing to consume at relatively small discounts while the remainder are fairly unresponsive to further price reductions.     

On the Rate of Convergence of Discrete‐Time Contingent Claims

This paper characterizes the rate of convergence of discrete‐time multinomial option prices. We show that the rate of convergence depends on the smoothness of option payoff functions, and is much lower than commonly believed because option payoff functions are often of all‐or‐nothing type and are not continuously differentiable. To improve the accuracy, we propose two simple methods, an adjustment of the discrete‐time solution prior to maturity and smoothing of the payoff function, which yield solutions that converge to their continuous‐time limit at the maximum possible rate enjoyed by smooth payoff functions. We also propose an intuitive approach that systematically derives multinomial models by matching the moments of a normal distribution. A highly accurate trinomial model also is provided for interest rate derivatives. Numerical examples are carried out to show that the proposed methods yield fast and accurate results.     

东北地区粮食型农户家庭农场经营风险认知的影响因素分析

［目的］东北地区作为维护国家粮食安全的“压舱石”,准确而系统地掌握东北地区粮食型农户家庭农场经营风险认知水平,为政府部门精准实施粮食型农户家庭农场配套扶持政策提供参考。［方法］文章利用黑龙江、吉林、辽宁3省301个粮食型农户家庭农场调研数据,运用交叉列表和多元有序logit模型分析家庭农场经营风险认知水平及其影响因素。［结果］（1）6312%的粮食型家庭农场有一定风险认知能力,土地经营面积在333~1333hm2（50~200亩）与1333~3333hm2（200~500亩）的家庭农场风险认知处于中等水平, 3333hm2（500亩）以上家庭农场经营风险认知低; （2）玉米种植型家庭农场风险认知水平高于水稻种植型家庭农场; （3）年龄、是否村干部、劳动力数量、土地经营规模、是否有自然灾害、农产品市场价格波动、是否“三品一标”认证、金融支持、农推人员技术指导和新型经营主体间合作稳定对东北地区粮食型农户家庭农场经营风险认知有影响。［结论］应培养家庭农场主个人特质,鼓励支农惠农政策向规模适度的家庭农场倾斜,从流程入手提高家庭农场风险防范能力。     

基于有序Logit-ISM模型的农村集体产权制度改革村民满意度影响因素研究——来自福建省的调查

[目的]农村集体产权制度改革是涉及亿万村民利益的重大制度创新,村民满意度是衡量改革绩效的主要标尺。研究农村集体产权制度改革村民满意度的影响因素,对提高村民满意度、提升改革绩效、深化改革发展具有重要意义。[方法]文章基于福建省农村固定观察点830份调研问卷数据,应用有序Logit回归模型分析村民对农村集体产权制度改革满意度的影响因素,并利用ISM模型进一步分析各影响因素间的逻辑关系与层级结构。[结果]（1）有序Logit模型回归结果显示,受教育程度、社会关系、家庭收入水平、公平感知、政策认知和村民参与对村民满意度产生了显著影响。（2） ISM模型分析发现,公平感知和政策认知是表层直接因素,村民参与是中层间接因素,社会关系、家庭收入水平和受教育程度是深层根源因素。[结论]为提升村民对改革的满意度,应加强改革宣导,拓宽参与渠道,建立反馈机制,积极推动村民参与改革、提升村民的公平感知和政策认知水平,同时发展壮大农村集体经济、增加村民财产性收入以增强村民获得感。     

A Dynamic Analysis of Fixed- and Adjustable-Rate Mortgage Terminations

This paper provides a side-by-side comparison of loan-level statistical models for fixed- and adjustable-rate mortgages. Multinomial logit models for quarterly conditional probabilities of default and prepayment are estimated. We find that the estimated impacts of embedded option values for prepayment and default are generally quite similar across both FRM and ARM loans, providing additional empirical support for the basic predictions of the options theory. We also find that differences in estimates of conditional probabilities of prepayment and default associated with mortgage age, origination period, original LTV, and relative loan size, indicate the continued significance of these other economic and demographic factors for empirical models of mortgage terminations.     

Biotechnology as a Technological Paradigm in the Global Knowledge Structure

The aim of this study is to analyse whether the receipt of public R&D funding determines firm's R&D strategy selection. This issue is crucial, as previous studies have shown that each R&D strategy is associated to a higher, or lower, innovation performance. We consider three R&D strategies – make, buy, make–buy – and three different sources of public funding – regional, state and other (such as EU). The model estimation is performed through a multinomial logit model with random effects with a sample of 457 large firms for the period 1992–2005, taken from the Spanish Survey of Business Strategies. The main finding is that the source of the funding influences whether firms select the make, buy or make–buy strategy. Additionally, because of the panel structure of the sample, we observe that the effect of public funding on the R&D strategy selection lasts longer for state and regional funds than for other funds.