Some maximum-indifference estimators for the slope of a univariate linear model

As known, the least-squares estimator of the slope of a univariate linear model sets to zero the covariance between the regression residuals and the values of the explanatory variable. To prevent the estimation process from being influenced by outliers, which can be theoretically modelled by a heavy-tailed distribution for the error term, one can substitute covariance with some robust measures of association, for example Kendall's tau in the popular Theil–Sen estimator. In a scarcely known Italian paper, Cifarelli [(1978), ‘La Stima del Coefficiente di Regressione Mediante l'Indice di Cograduazione di Gini’, Rivista di matematica per le scienze economiche e sociali, 1, 7–38. A translation into English is available at http://arxiv.org/abs/1411.4809 and will appear in Decisions in Economics and Finance] shows that a gain of efficiency can be obtained by using Gini's cograduation index instead of Kendall's tau. This paper introduces a new estimator, derived from another association measure recently proposed. Such a measure is strongly related to Gini's cograduation index, as they are both built to vanish in the general framework of indifference. The newly proposed estimator is shown to be unbiased and asymptotically normally distributed. Moreover, all considered estimators are compared via their asymptotic relative efficiency and a small simulation study. Finally, some indications about the performance of the considered estimators in the presence of contaminated normal data are provided.     

大型科研项目的风险管理流程与风险决策

针对大型科研项目风险管理的特点,设计了其风险管理流程;根据风险决策原理,结合实例探讨了灰局势决策法在大型科研项目中的应用,所获得的决策结果是进行风险处理的基础和重要依据,对风险管理实践有一定的指导意义。     

被告人程序选择权的界定及其正当性探析

作为刑事被告人人权保障的一个方面,现代法治国家普遍尊重并在不同程度上赋予了被告人以程序选择权--即在法定范围内,被告人有权依自己的意愿选择刑事诉讼的有关程序及与程序有关的事项,具体如对审判程序的选择和对审判方式的选择.虽然程序选择权未被表述为被告人最基本、最重要的诉讼权利,但因其有着广泛的理论依据从而具备了存在和发展的正当性,故在我国的刑事诉讼中也应当受到重视.     

美国制裁国际卡特尔的赦免制度介评

美国反垄断部门出台的赦免制度在制裁国际卡特尔方面发挥着极为重要的作用,该制度规定参加卡特尔的公司中第一个向政府揭发该卡特尔的公司可免除刑事责任。赦免制度有效实施的基础包括三个方面,即管辖地的反垄断法必须对参与卡特尔的公司制定严厉的惩罚措施、卡特尔成员面临着被反垄断部门查处的巨大风险、赦免制度具有透明度和可预见性。美国的赦免制度已相当成熟和完善,实践也证明这一制度具有极大的应用价值,这对于我国制定反垄断法、有效制裁国际卡特尔具有重要的借鉴意义。     

Heterogeneous treatment effects on Children's cognitive/non-cognitive skills: A reevaluation of an influential early childhood intervention

The 1962–67 High/Scope Perry Preschool Program, a well-known experimental early childhood intervention study that provided quality preschool education to disadvantaged children, has been shown to have had positive impacts on early child development and on a variety of adulthood outcomes. However, most previous analyses have only examined average treatment effects across all program participants without exploring possible effect heterogeneity by children's background characteristics. We investigated this question by first using the 1964–65 Current Population Survey data in combination with the Perry data to construct a scale of child socioeconomic status based on the estimated propensity for inclusion in the Perry program, then analyzing effect heterogeneity within the Perry sample by strata of our socioeconomic scale. We found that the treatment effects of enrollment in the Perry preschool on cognitive and non-cognitive skills were much larger and more persistent among the most disadvantaged children than among others in the Perry program. Furthermore, among the most disadvantaged children, the treatment (i.e., preschool enrollment) affects later outcomes through a reinforcement mechanism of skill development (i.e., early cognitive gain leads to a non-cognitive gain, which in turn leads to later cognitive gain) and a sequential improvement of cognitive skills over time. These findings have important implications for the evaluation of policy interventions in early child development using experimental data.     

EVALUATING THE IMPLEMENTATION OF THE PRISON RAPE ELIMINATION ACT (PREA): A “LESSONS LEARNED” APPROACH

The Prison Rape Elimination Act (PREA) was designed to address sexual violence in prison. While previous has focused on sexual violence occurring in correctional facilities, there has been a dearth of studies that document the expertise, experience, or reflections of program following the cimplementation of PREA- within a correctional system. The current study utilizes a “lessons learned” approach to discuss the impact of the PREA Demonstration Project on a state prison system that includes 19 correctional institutions. Results indicate the benefits of merging the philosophical orientation of key stakeholders, establishing benchmarks, and the need for partnerships with prosecutors. A comparison of the perceptions of correctional administrators, inmates, and front-line correctional officers regarding PREA is included. Also featured are the “lessons learned” from the implementation of PREA into four prison sites, along with the concept of building trust and the impact of lockdowns due to staff shortages.     

An E-learning outreach program for public schools: Findings and lessons learned based on a pilot program in Makati City and Cabuyao City,Laguna, Philippines

The E-Learning Outreach Program (ELOP) is a multisectoral, collaborative, and commitment-driven action research that focuses on providing relevant and useful computer and Internet literacy short courses for public elementary students. This study presents the critical action plans of setting up a pilot e-Learning station in Hen. Pio del Pilar Elementary School in Makati City and in Pulo Elementary School in Cabuyao City, Laguna, Philippines. The school’s computer laboratory was converted to an E-Learning station with additional devices and technical support from De La Salle University (DLSU). The study aims to account for a process-based heuristic approach in laying down the different phases of the program, specifically to: (1) coordinate and orient parents, pupils, teachers and school administrators, (2) set-up an e-Learning environment (3) design and write course modules (4) assess learning skills and experience of pupils, and (5) evaluate the program based on research team’s observation and results of the focus group discussion (FGD) with teachers and student-participants. In Pulo Elementary School, a pretest and posttests were conducted with results showing that the program has improved participants’ e-Learning knowledge and skills except for advance skills in hardware utilization. The participants also showed a strong positive attitude towards the ELOP.     

A Generalization of Wendell's Tolerance Approach to Sensitivity Analysis in Linear Programming

A criticism of linear programming has been that the data which are available in practice are too inexact and unreliable for linear programming to properly work. Managers are therefore concerned with how much actual values may differ from the estimates that were used in the model before the results become irrelevant. Sensitivity analysis emerged to help deal with the uncertainties inherent in the linear programming model. However, the ranges calculated are generally valid only when a single coefficient is varied. An extension of sensitivity analysis, the 100 Percent Rule, allows the simultaneous variation of more than one element in a vector, but does not permit the independent variation of the elements. A tolerance approach to sensitivity analysis enables the consideration of simultaneous and independent change of more than one coefficient. However, the ranges developed are unnecessarily restricted and may be reduced in width to zero when primal or dual degeneracy exists. This paper presents an extension of the tolerance approach which reduces the limitations of both the traditional and tolerance approaches to sensitivity analysis.     

A Comment on Second-Order Polynomial Regression Models

In a recent article, Chatterjee and Greenwood [1] addressed the problem of multicollinearity in polynomial regression models. They noted that there is a high correlation between X and X²; therefore, a second-order polynomial model suffers the consequences of collinearity. Chatterjee and Greenwood [1] suggested a method they believe will overcome the problem. The contention of the present comment is that the suggested method accomplishes nothing and, indeed, has the potential to lead the unwary researcher to the wrong inference and misinterpretation of his results.     

Sensitivity Analysis in Linear Programming Models with Common Inputs

The importance of sensitivity analysis information in linear programming has been stressed in the management science literature for some time. Indeed, Gal [3] has devoted an entire text to just this issue. Linear programs with common inputs (cost coefficients or right-hand-side values) present a problem in that classical sensitivity analysis does not allow for the simultaneous changes required to determine the sensitivity of these models to common inputs. We first survey the approaches previously developed for simultaneous-change sensitivity analysis and cast them in the framework of the special common input case. These general techniques are compared to a simple aggregate variable technique that has not received attention in the literature.