逐次定数截尾下Weibull分布参数的逆矩估计

基于逐次定数截尾样本下,讨论了两参数Weibull分布的参数估计,得到了两参数的逆矩估计.并利用模拟方法与极大似然估计作比较,模拟结果表明逆矩估计优于极大似然估计。     

质量文化的评价尺度和评价维度研究

文章提出了质量文化的评价尺度和评价维度问题,阐述了评价尺度——先进性的选择方法,描述了评价尺度的表现和特征,论述了一级评价维度——基本层面和二级评价维度——内涵要素,总结了评价维度与评价尺度的对应关系,构建了评价框架。     

一种基于均值量化的小波域自同步数字音频水印算法

提出了一种基于均值量化的小波域自同步数字音频水印算法。该算法是一种盲检测算法,检测时不需要原始音频信号。算法引入了系数均值量化的思想,音频信号进行小波分解后,对其中的低频系数进行均值量化,嵌入水印;并且引入了嵌入同步信号的思想,利用同步信号来定位水印的嵌入位置,以抵抗平移、裁剪等攻击。实验结果表明该算法具有较强的鲁棒性和抗攻击性。     

The Institutionalist Perspective on Recent Theories of Direct Foreign Investment: A Comment on McClintock

This article holistically addresses the effective (relative) income tax contribution of a given income (or, wealth) group. The widely acclaimed standard in public policy is the absolute benefaction of a given income group in filling up the fiscal coffers. Instead, we focus on the ratio of the average income tax rate of an income group divided by the percentage of national income (or wealth) appropriated by the same income group. In turn, we develop the Fiscal Inequality Coefficient which compares the effective percentage income tax payments of pairs of income (or wealth) groups. Using data for the United States, we concentrate on pairs such as the Bottom 90% versus Top 10%, Bottom 99% versus Top 1%, and Bottom 99.9% versus Top 0.1%. We conclude that policy makers with a strong social conscience should re-evaluate the progressivity of the income tax system and make the richest echelons of the income and wealth distributions pay a fairer and higher tax.     

Option Pricing For Jump Diffusions: Approximations and Their Interpretation

We derive a computable approximation for the value of a European call option when prices satisfy a jump-diffusion model with the coefficients depending explicitly on time. This is achieved by approximating the original coefficients with functions that are piecewise constant in time. We give an interpretation of the approximating option values, in particular in the context of a discrete-time model associated with the approximating continuous-time model.     

英语教师角色转变中的利器——配对均值假设检验

假设检验是数理统计学研究的一个重要部分,是研究比较不可或缺的部分,是教师由教学型向教研型转变、实现教学研究两条腿走路的法宝,是展示成果有力的分析工具。从英语学科出发,实例探讨假设检验在其中的应用,具体展示其分析论证的强大作用,以期为英语教师成长、实现教学向教研型转变提供范例。     

China's changing diet and its impacts on greenhouse gas emissions: an index decomposition analysis

With increasing awareness of agriculture's contribution to global greenhouse gases (GHGs) and China's position as the world's top GHG emitter, there is heightened attention to the embodied emissions in China's food consumption. China's diet has shifted to include more fruit, vegetables, meat and dairy. Not surprisingly, GHG emissions from food consumption have also increased substantially. This analysis links China's food consumption with the emissions of food production industries in China and its trade partners to determine the effects of dietary change on GHGs since 1989. We utilise high‐resolution food production and emissions data to perform a logarithmic mean Divisia index decomposition to attribute changes in GHG emissions to the scale, supply structure, demand structure and efficiency effects resulting from Chinese dietary changes over a 20‐year period. This study finds that while countries supplying food to China contribute little to China's food‐related GHGs, demands for meat and dairy play a much larger role, driving up emissions. The overall scale of increased consumption of all food further propels growth in GHG emissions. Results indicate, however, that while food consumption in China more than doubles between 1989 and 2009 improvements in technological efficiency limit the rate of increase.     

BETTER THAN DYNAMIC MEAN‐VARIANCE: TIME INCONSISTENCY AND FREE CASH FLOW STREAM

As the dynamic mean‐variance portfolio selection formulation does not satisfy the principle of optimality of dynamic programming, phenomena of time inconsistency occur, i.e., investors may have incentives to deviate from the precommitted optimal mean‐variance portfolio policy during the investment process under certain circumstances. By introducing the concept of time inconsistency in efficiency and defining the induced trade‐off, we further demonstrate in this paper that investors behave irrationally under the precommitted optimal mean‐variance portfolio policy when their wealth is above certain threshold during the investment process. By relaxing the self‐financing restriction to allow withdrawal of money out of the market, we develop a revised mean‐variance policy which dominates the precommitted optimal mean‐variance portfolio policy in the sense that, while the two achieve the same mean‐variance pair of the terminal wealth, the revised policy enables the investor to receive a free cash flow stream (FCFS) during the investment process. The analytical expressions of the probability of receiving FCFS and the expected value of FCFS are derived.     

MEAN VARIANCE PREFERENCES, EXPECTATIONS FORMATION, AND THE DYNAMICS OF RANDOM ASSET PRICES

This paper analyzes the dynamics of an explicit random process of prices and price expectations of finitely many assets in an economy with overlapping generations of heterogeneous consumers. They maximize expected utility with respect to subjective transition probabilities defined by Markov kernels which describe the forecasting behavior of agents. Given such forecasting rules (predictors) and an exogenous process of dividends, the evolution of equilibrium asset prices and expectations is described by a random dynamical system in the sense of Arnold (1998) . The paper investigates the long-run behavior (stationary solutions) by proving the existence and stability of random fixed points for mean-variance preferences under various predictors, including unbiased predictions, and adaptive, as well as OLS forecasting. An explicit characterization of rational expectations solutions is given, providing a full dynamic characterization of asset price processes for the classical CAPM in the case of stationary OLG economies. Numerical simulations are used to compare the performance of the different predictors under an AR(1) dividend process.     

RISK MEASURES: RATIONALITY AND DIVERSIFICATION

When there is uncertainty about interest rates (typically due to either illiquidity or defaultability of zero coupon bonds) the cash‐additivity assumption on risk measures becomes problematic. When this assumption is weakened, to cash‐subadditivity for example, the equivalence between convexity and the diversification principle no longer holds. In fact, this principle only implies (and it is implied by) quasiconvexity. For this reason, in this paper quasiconvex risk measures are studied. We provide a dual characterization of quasiconvex cash‐subadditive risk measures and we establish necessary and sufficient conditions for their law invariance. As a byproduct, we obtain an alternative characterization of the actuarial mean value premium principle.