Polynomial Spline Estimation for a Generalized Additive Coefficient Model

Abstract.  We study a semiparametric generalized additive coefficient model (GACM), in which linear predictors in the conventional generalized linear models are generalized to unknown functions depending on certain covariates, and approximate the non-parametric functions by using polynomial spline. The asymptotic expansion with optimal rates of convergence for the estimators of the non-parametric part is established. Semiparametric generalized likelihood ratio test is also proposed to check if a non-parametric coefficient can be simplified as a parametric one. A conditional bootstrap version is suggested to approximate the distribution of the test under the null hypothesis. Extensive Monte Carlo simulation studies are conducted to examine the finite sample performance of the proposed methods. We further apply the proposed model and methods to a data set from a human visceral Leishmaniasis study conducted in Brazil from 1994 to 1997. Numerical results outperform the traditional generalized linear model and the proposed GACM is preferable.     

Testing for order among K populations: theory and examples

Testing for stochastic order among K populations is a common and important problem in statistical practice. It arises in the analysis of both planned experiments and observational studies. The authors develop a new nonparametric test for order among K populations that can accommodate any stochastic ordering. The test is based on a maximally selected chi‐bar‐square statistic. The authors find its limiting distribution and use simulations to derive critical values. Three important examples are used to illustrate the applicability of the general method. The authors find that the new tests outperform the existing methods in many practical cases. The Canadian Journal of Statistics 38: 97–115; 2010 © 2009 Statistical Society of Canada     

面临汇率和供应风险的双渠道采购决策研究

多渠道采购是制造商降低采购风险的有效手段之一。本文考虑一个制造商向两个供应商进行联合采购的最优决策问题。其中本土(国内)供应商价格稳定,但供应不可靠;母国(国外)供应商供应可靠,但实际价格受汇率波动影响。本文研究了制造商在风险厌恶情形下的最优联合采购决策,并与风险中性情形进行了比较。研究表明,风险中性制造商只会向一个供应商采购;而风险厌恶制造商的采购决策会受到供应可靠性、汇率的波动以及两者相关关系的影响。具体来说,当产品合格率和汇率相对独立时,风险厌恶的制造商倾向于单渠道采购;当合格率和汇率相关时则可能选择双渠道采购以分散风险。数值实验表明,双渠道采购可以有效降低制造商的损失风险。     

奖惩机制下制造商竞争的闭环供应链决策模型

本文分别建立了集中式决策,无奖惩机制的分散式决策以及奖惩机制下考虑制造商竞争的闭环供应链决策模型。通过逆向归纳法对三种情况下决策变量的求解与比较,分别得到了闭环供应链的回购价、批发价、零售价及回收率。研究表明：与无奖惩机制下的分散式决策情形相比,政府奖惩机制能有效引导制造商降低新产品价格、提高回收率、增加闭环供应链各成员企业的利润,同时有利于增加消费者的利益;奖惩机制下主动回收废旧产品的制造商利润增加,不回收的制造商利润降低,有效引导了制造商的回收积极性,同时回收商与零售商利润的增加也提高了她们参与闭环供应链的积极性,进而使得整个闭环供应链的成员企业有效协调。     

奖惩机制下具竞争制造商的废旧产品回收决策模型

各国政府为保护环境加强了对废旧电器电子产品的回收再制造的管制。本文研究了两个制造商竞争情况下基于政府奖惩机制的制造商的废旧产品回收决策问题。具体研究时分两种情况:一种情况是两个制造商中只有一个回收再制造废旧产品,另一种情况是两个制造商都回收再制造废旧产品。研究表明:奖惩机制下回收再制造废旧产品的制造商的回收率提高;无论制造商是否回收再制造废旧产品,其新产品销售价均比无奖惩机制时低,奖惩机制对消费者有利;制造商竞争有利于奖惩机制引导制造商提高废旧产品的回收率;回收率随再制造率的提高而提高;无论另一个制造商回收再制造废旧产品与否,实施回收再制造制造商的利润随奖惩力度的提高而增加,随政府规定的目标回收率的提高而降低,且奖惩力度越大,降低幅度越明显。算例分析说明了上述结论的正确性。     

银行间同业拆借利率的复杂性研究

本文运用复杂性理论对我国银行间同业拆借利率进行了实证研究.通过银行间同业拆借利率的关联积分关于相空间维数的数值计算发现,当相空间维数大于9以后,关联维数趋于平稳,从而确定银行间同业拆借利率的嵌入维数约为9,这时对应的关联维数约为3.64.通过对Kolmogorov熵的计算得出,我国7天银行间同业拆借利率的可预测时间尺度约为7天.本文将H.E.Hurst提出的R/S分析法应用于我国银行间同业拆借利率分析.测定了我国银行问同业拆借利率收益率的Hurst指数.运用消除趋势波动分析方法,计算了我国银行问同业拆借利率收益率的标度指数.结果表明:银行间同业拆借利率显示为状态反持续性.     

Fisher's Information for Discretely Sampled Lévy Processes

This paper studies the asymptotic behavior of Fisher's information for a Lévy process discretely sampled at an increasing frequency. As a result, we derive the optimal rates of convergence of efficient estimators of the different parameters of the process and show that the rates are often nonstandard and differ across parameters. We also show that it is possible to distinguish the continuous part of the process from its jumps part, and even different types of jumps from one another.     

Eliciting Risk and Time Preferences

We design experiments to jointly elicit risk and time preferences for the adult Danish population. Since subjects are generally risk averse, we find that joint elicitation provides estimates of discount rates that are significantly lower than those found in previous studies and more in line with what would be considered as a priori reasonable rates. The statistical specification relies on a theoretical framework that involves a latent trade‐off between long‐run optimization and short‐run temptation. Estimation of this specification is undertaken using structural, maximum likelihood methods. Our main results based on exponential discounting are robust to alternative specifications such as hyperbolic discounting. These results have direct implications for attempts to elicit time preferences, as well as debates over the appropriate domain of the utility function when characterizing risk aversion and time consistency.     

Steuerreformen durch Tarif-oder Zeiteffekte? Eine Analyse am Beispiel der Thesaurierungsbegünstigung für Personenunternehmen

Zusammenfassung  Der Beitrag diskutiert Tarif- und Zinseffekte anhand der begünstigten Besteuerung nicht entnommener Gewinne von Personengesellschaften, die 2008 in Deutschland eingeführt wurde. Bei Eigenfinanzierung und Betrachtung von Grenzsteuers?tzen zeigt der Beitrag, dass die Thesaurierungsbegünstigung stets nachteilig ist, wenn eine abgeltend besteuerte private Kapitalmarktanlage die Alternativanlage darstellt. Müssen Gewinne thesauriert werden, weil Mittel im Unternehmen ben?tigt werden, so entf?llt die private Alternativanlage und die Thesaurierungsbegünstigung kann bei hohen Zins- und Steuers?tzen vorteilhaft sein. Wird die Einkommensteuerprogression berücksichtigt, zeigt der Beitrag, dass bei schwankenden Gewinnen die Thesaurierungsbegünstigung oftmals vorteilhaft ist, auch gegenüber der Abgeltungsteuer. Bei fremdfinanzierten Investitionen kann die Inanspruchnahme der Thesaurierungsbegünstigung sehr vorteilhaft sein, da die geringere Steuerzahlung bei Gewinnanfall den Umfang des ben?tigten Fremdkapitals mindert. Insgesamt zeigt sich, dass sich Reformen von Steuertarifen wesentlich st?rker auf die Vorteilhaftigkeit von Investitionen auswirken als Zinseffekte.

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Tax reforms by tax rate effects or timing effects? An analysis based an the German tax privilege for retained earnings

Summary  This paper analyzes two typical effects of tax reforms, tax rate effects and timing effects. The example chosen for the analysis is the tax privilege for retained profits of partnerships and sole proprietorships, which was implemented in Germany in 2008. Taking equity-financing and top marginal tax rates into account, the so-called tax privilege turns out to be a disadvantage under most assumptions. If the alternative investment is private capital income taxed at a flat-rate tax, the tax privilege will always be disadvantageous. If profits have to be retained and business income is the alternative investment, then the tax privilege will be advantageous in case of high income tax rates and interest rates. Analyzing progressive tax rates instead of top marginal tax rates reveals favorable results in case of fluctuating profits if the tax privilege is claimed. The same is true if debtfinancing is taken into account. All in all, the paper shows that a reform of tax rates influences the attractiveness of investments much more compared to timing effects.

     

Rate of Foot-and-Mouth Disease Virus Transmission by Carriers Quantified from Experimental Data

Upon infection with foot-and-mouth disease virus (FMDV) a considerable number of animals become carriers of the virus. These carriers are considered to be a risk for new outbreaks, but the rate at which these animals can transmit the infection has not been quantified. An analysis was carried out using data from previously published experiments in order to quantify the transmission rate parameter β of FMDV infection from carriers to susceptible animals. The parameter β was estimated at 0.0256 (likelihood-based confidence interval: 0.008–0.059) infections per carrier per month. Moreover, analysis of published experimental data indicates that the proportion of FMDV carriers decreases at a rate of 0.115 per month. Both parameters obtained from this study are useful for quantitative risk analyses of the trade of animals from FMDV-infected areas or the lifting of vaccination programs.