控股股东掏空动机与多元化的盈余波动效应

多元化经营是公司关注的重大发展问题,因此,多元化经营的动机及其经济后果也成为学者们研究的重点话题。本文从我国上市公司的多元化经营与盈余波动性之间的关系入手对这一问题进行研究,具体分析了公司多元化经营的程度对盈余波动性的影响及控股股东的掏空动机对多元化盈余波动效应的作用。研究发现,我国上市公司的多元化经营显著降低了公司的盈余波动性,多元化程度越高,盈余的波动性越低;但由控股股东代理问题而形成的掏空动机损害了多元化的盈余波动效应。本文的研究为多元化的经济后果增添了新的文献,同时也为上市公司监管提供了参考依据。     

History matters: The impact of reviews and sales of earlier versions of a product on consumer and expert reviews of new editions

Product reviews are assumed to be based on the observable characteristics of the underlying product. However, in the case of new editions in a product series, the determinants may include signals that originate from the reviews and the sales of editions that precede the focal product edition. Our analysis of 577 video games released in a series between 2000 and 2009 indicates that the reviews of earlier versions carry over to the reviews of the sequel by the same type of reviewer. We also find that expert reviews are influenced by the average review of previous editions by consumers and the average sales of previous editions of the product. This suggests that experts tend to adapt to the taste of consumers. Furthermore, it is found that a lack of consensus, between reviewers of a particular type, weakens the impact of average past reviews, whilst it magnifies the impact of the sales of earlier versions.     

Fitting Second-Order Finite Mixture Models to Data with Many Censored Values Using Maximum Likelihood Estimation

Finite mixture models, that is, weighted averages of parametric distributions, provide a powerful way to extend parametric families of distributions to fit data sets not adequately fit by a single parametric distribution. First-order finite mixture models have been widely used in the physical, chemical, biological, and social sciences for over 100 years. Using maximum likelihood estimation, we demonstrate how a first-order finite mixture model can represent the large variability in data collected by the U.S. Environmental Protection Agency for the concentration of Radon 222 in drinking water supplied from ground water, even when 28% of the data fall at or below the minimum reporting level. Extending the use of maximum likelihood, we also illustrate how a second-order finite mixture model can separate and represent both the variability and the uncertainty in the data set.     

修辞的解构及其审美心理探微

修辞的解构是打破语言规范和常理的一类变异用法 ,它是修辞运用中的普遍现象 ,并具有语用和审美功能。同时文章剖析了其审美心理生成原理 ,推定“距离产生美”是其解构的心理生成机制     

对纵贯数据统计分析的认识

在介绍了纵贯数据的设计思想及优缺点基础上,从统计方法的角度讨论了纵贯数据在社会科学中所能发挥的作用。纵贯数据的优点在于其可以帮助我们进行对总体异质性的识别、对因果机制干预的研究、对因果效应的研究和对状态变换的研究。以一些基于纵贯数据的研究设计为实例,文章阐述了在研究中假设与数据紧密衔接的重要性,以及利用统计方法分析纵贯数据时需要考虑的要点。但由于存在着由人类和人类行为内在变异性导致的这一无法避免的根本性缺陷,纵贯数据并不能解决所有问题。因而在纵贯数据的辅助下,研究者需要对社会现象有更深入的理解,将其进行更合理的概念化,并加以更精准的数据分析。     

Methods for Characterizing Variability and Uncertainty: Comparison of Bootstrap Simulation and Likelihood-Based Approaches

Variability arises due to differences in the value of a quantity among different members of a population. Uncertainty arises due to lack of knowledge regarding the true value of a quantity for a given member of a population. We describe and evaluate two methods for quantifying both variability and uncertainty. These methods, bootstrap simulation and a likelihood-based method, are applied to three datasets. The datasets include a synthetic sample of 19 values from a Lognormal distribution, a sample of nine values obtained from measurements of the PCB concentration in leafy produce, and a sample of five values for the partitioning of chromium in the flue gas desulfurization system of coal-fired power plants. For each of these datasets, we employ the two methods to characterize uncertainty in the arithmetic mean and standard deviation, cumulative distribution functions based upon fitted parametric distributions, the 95th percentile of variability, and the 63rd percentile of uncertainty for the 81st percentile of variability. The latter is intended to show that it is possible to describe any point within the uncertain frequency distribution by specifying an uncertainty percentile and a variability percentile. Using the bootstrap method, we compare results based upon use of the method of matching moments and the method of maximum likelihood for fitting distributions to data. Our results indicate that with only 5–19 data points as in the datasets we have evaluated, there is substantial uncertainty based upon random sampling error. Both the boostrap and likelihood-based approaches yield comparable uncertainty estimates in most cases.     

Variability and Uncertainty Meet Risk Management and Risk Communication

In the past decade, the use of probabilistic risk analysis techniques to quantitatively address variability and uncertainty in risks increased in popularity as recommended by the 1994 National Research Council that wrote Science and Judgment in Risk Assessment. Under the 1996 Food Quality Protection Act, for example, the U.S. EPA supported the development of tools that produce distributions of risk demonstrating the variability and/or uncertainty in the results. This paradigm shift away from the use of point estimates creates new challenges for risk managers, who now struggle with decisions about how to use distributions in decision making. The challenges for risk communication, however, have only been minimally explored. This presentation uses the case studies of variability in the risks of dying on the ground from a crashing airplane and from the deployment of motor vehicle airbags to demonstrate how better characterization of variability and uncertainty in the risk assessment lead to better risk communication. Analogies to food safety and environmental risks are also discussed. This presentation demonstrates that probabilistic risk assessment has an impact on both risk management and risk communication, and highlights remaining research issues associated with using improved sensitivity and uncertainty analyses in risk assessment.     

中介语语体可变性与语体失误

语体的选择直接影响到语言交际的效果。英语中介语语体具有可变性特点,通过各种语体失误表现出来。克服语体失误的教学对策主要包括传授语体知识,强化语体意识,设置虚拟语境进行大量的语体转换练习,提高语体能力。     

Using a Lag Schedule of Reinforcement to Increase Response Variability in Children With Autism Spectrum Disorders

Lag reinforcement schedules have been shown in previous research to be an effective intervention for teaching verbal and nonverbal response variability to individuals with developmental disabilities. In more recent research, variability itself has been considered a reinforceable behavior in its own right (Susa & Schlinger, The Analysis of Verbal Behavior, 18, 125–130, 2012). Lag x schedules of reinforcement can be used to teach variability by using contingencies that require responses to differ from previous responses. The present study extended Susa and Schlinger’s, The Analysis of Verbal Behavior, 18, 125–130, (2012) research by using 3 social questions instead of 1 in a random rotation and included probes to test for generality. A changing-criterion design was used to evaluate the results with one 11-year-old female participant diagnosed with autism. During baseline, the participant provided little variability, with rote responses. During the Lag 1 and Lag 2 phases, appropriate variable verbal responding increased with the use of echoic prompts, visual aids, and an error correction procedure. Further, the results also showed that the participant learned to vary her responses by demonstrating the ability to emit 11 novel prompted responses and 13 spontaneous responses.In addition, the participant was able to retain the skills learned in a maintenance probe conducted 4 weeks postintervention.