An Empirical Model of Perceived Mortality Risks for Selected U.S. Arsenic Hot Spots

Researchers have long recognized that subjective perceptions of risk are better predictors of choices over risky outcomes than science‐based or experts’ assessments of risk. More recent work suggests that uncertainty about risks also plays a role in predicting choices and behavior. In this article, we develop and estimate a formal model for an individual's perceived health risks associated with arsenic contamination of his or her drinking water. The modeling approach treats risk as a random variable, with an estimable probability distribution whose variance reflects uncertainty. The model we estimate uses data collected from a survey given to a sample of people living in arsenic‐prone areas in the United States. The findings from this article support the fact that scientific information is essential to explaining the mortality rate perceived by the individuals, but uncertainty about the probability remains significant.     

A VARYING-COEFFICIENT APPROACH TO ESTIMATION AND EXTRAPOLATION OF HOUSEHOLD SIZE

Household formation analysis is both a multidimensional economical and statistical problem of great complexity. Since most of the literature tries to incorporate multiple economic aspects, there is, considering the extraordinary practical relevance of the problem, a remarkable gap between theory and application in this field. This paper tries to diminish this gap by a comprehensive treatise on the statistical site of the problem. Thus, we develop a model of household composition, where the evolution of the household membership rates is captured by a logit link-function and a multinomial distribution, which automatically fulfills the non-negativity and adding-up restrictions of the underlying probabilities. We use a varying-coefficients procedure by polynomially smoothing the household membership rates over age for every household size class and assuming a linear predictor in other variables. As an application we estimated and extrapolated the distribution of household sizes of an autonomous region using population register data. Our sample consisted of approximately 450,000 people living in about 170,000 households, grouped into nine different household size classes and classified into age classes from 0 to 90. The data covers a time span of 12 years, from 1986 to 1997. Empirical results show the robustness of the procedure even in case of low cell frequencies. Thus, there is no need for regional or age-group aggregations.     

HAZARD RATE ESTIMATION FOR CENSORED DATA BY WAVELET METHODS

ABSTRACT

We study the estimation of a hazard rate function based on censored data by non-linear wavelet method. We provide an asymptotic formula for the mean integrated squared error (MISE) of nonlinear wavelet-based hazard rate estimators under randomly censored data. We show this MISE formula, when the underlying hazard rate function and censoring distribution function are only piecewise smooth, has the same expansion as analogous kernel estimators, a feature not available for the kernel estimators. In addition, we establish an asymptotic normality of the nonlinear wavelet estimator.     

Convergence Rate of Wavelet Expansions of Gaussian Random Processes

This article characterizes uniform convergence rate for general classes of wavelet expansions of stationary Gaussian random processes. The convergence in probability is considered.     

公交专用道对车辆间隔时间的影响分析

我国很多大城市都采用公交专用道的形式来缓解公交出行效率低，公交竞争力差的状况，主要研究公交专用道的设置对车辆间隔时间的影响程度。首先对有公交专用道的线路进行了调查取样，通过对样本数据的拟合与检验，并且对比无专用道的公交线路样本数据，得出结论：公交专用道的设置对车辆间隔时间有很大的影响作用。     

Women's Hair Color and Survey Response Rate: A Field Experiment

Previous research found that survey response rates were influenced by physical characteristics of the interviewer. However, the effect of hair color on compliance to a survey request has never been studied. Female confederates wearing blond, brown, black, or red wigs solicited 1,200 male and female pedestrians for a survey. It was found those male passersby, but not the female, agreed more frequently to the confederates wearing blond wigs whereas they agreed less to the same confederates wearing red wigs. Greater youth and healthiness associated with blond hair in women is used to explain these results. The practical interest in face-to-face surveys is addressed.     

A Bayesian discovery procedure

Summary.  We discuss a Bayesian discovery procedure for multiple-comparison problems. We show that, under a coherent decision theoretic framework, a loss function combining true positive and false positive counts leads to a decision rule that is based on a threshold of the posterior probability of the alternative. Under a semiparametric model for the data, we show that the Bayes rule can be approximated by the optimal discovery procedure, which was recently introduced by Storey. Improving the approximation leads us to a Bayesian discovery procedure, which exploits the multiple shrinkage in clusters that are implied by the assumed non-parametric model. We compare the Bayesian discovery procedure and the optimal discovery procedure estimates in a simple simulation study and in an assessment of differential gene expression based on microarray data from tumour samples. We extend the setting of the optimal discovery procedure by discussing modifications of the loss function that lead to different single-thresholding statistics. Finally, we provide an application of the previous arguments to dependent (spatial) data.     

概率准则下的两期投资决策问题

概率准则是以期望收益率为导向的, 是某些情况下投资者的投资决策准则, 它具有一定 的现实指导意义. 在一般情况下, 证券收益率在不同时期的概率分布会不同而且相关. 因此, 提 出了一类概率准则下的两期投资决策问题, 建立了其数学模型. 对于证券收益率为连续及离散 型随机变量这两种情况分别进行了讨论, 给出了求解最优策略的方法及投资决策的步骤, 并举 例予以了说明.     

论经济增长速度和经济效益

经济增长速度和经济效益是两个不同但又相互密切联系的概念。经济增长是长、短两个不同时期的新增产值的对比,而经济效益则涉及不同时期的利润与总成本的对比。在长期中,经济效益是经济保持一定增长速度的基础,因为经济的长期增长取决于利润持续转化为投资,而只有不断改善经济结构、提高技术水平和产品档次,才能有高利润率（高效益）,才能有持续的新增投资,并取得理想的增长速度。但是在短期内,没有速度就一定没有效益,因为成本刚性在短期里难以克服。在剩余劳动力较多的国家,保持一定的经济增长速度也是取得社会效益的前提。中国的国情决定了中国必须在提高技术水平和广泛利用劳动力之间达到有效的协调。     

投资方案内部收益率的分析

本文严格地证明了投资方案的内部收益率(IRR)与借款利率的关系,全部资金与自有资金的内部收益率的关系,以及不同的借款偿还方式对自有奖金内部收益率的影响。