A Graphical Tool for Interpreting Regression Coefficients of Trinomial Logit Models

Multinomial logit (also termed multi-logit) models permit the analysis of the statistical relation between a categorical response variable and a set of explicative variables (called covariates or regressors). Although multinomial logit is widely used in both the social and economic sciences, the interpretation of regression coefficients may be tricky, as the effect of covariates on the probability distribution of the response variable is nonconstant and difficult to quantify. The ternary plots illustrated in this article aim at facilitating the interpretation of regression coefficients and permit the effect of covariates (either singularly or jointly considered) on the probability distribution of the dependent variable to be quantified. Ternary plots can be drawn both for ordered and for unordered categorical dependent variables, when the number of possible outcomes equals three (trinomial response variable); these plots allow not only to represent the covariate effects over the whole parameter space of the dependent variable but also to compare the covariate effects of any given individual profile. The method is illustrated and discussed through analysis of a dataset concerning the transition of master’s graduates of the University of Trento (Italy) from university to employment.     

善是什么

善恶观念的产生要从物质实践出发来解释。对什么是善的问题 ,西方伦理学家们依据自己不同的研究方法 ,各抒己见 ,这些观点有其合理性 ,同时也存在着不可避免的缺陷 ,追问善的问题 ,离不开对善恶关系的探讨 ,善恶是相对的 ,同时也存在着客观的评价标准。考察善是什么 ,必须将动机与效果统一起来才能把握     

关于建立股指期货交易制度的构想

随着中国正式加入WTO ,推出股票指数期货已是确定的方向。目前中国建立股指期货交易制度不仅是必要的 ,也是可行的。股指期货作为一种金融创新产品 ,它的建立首先必须有统一交易场所 ,科学设计合约 ,同时也要进一步规范现货市场 ,培育交易主体 ,引入做空机制 ,规范会员结构 ,健全监管制度     

A Bayesian Adjustment for Covariate Misclassification with Correlated Binary Outcome Data

Estimated associations between an outcome variable and misclassified covariates tend to be biased when the methods of estimation that ignore the classification error are applied. Available methods to account for misclassification often require the use of a validation sample (i.e. a gold standard). In practice, however, such a gold standard may be unavailable or impractical. We propose a Bayesian approach to adjust for misclassification in a binary covariate in the random effect logistic model when a gold standard is not available. This Markov Chain Monte Carlo (MCMC) approach uses two imperfect measures of a dichotomous exposure under the assumptions of conditional independence and non-differential misclassification. A simulated numerical example and a real clinical example are given to illustrate the proposed approach. Our results suggest that the estimated log odds of inpatient care and the corresponding standard deviation are much larger in our proposed method compared with the models ignoring misclassification. Ignoring misclassification produces downwardly biased estimates and underestimate uncertainty.     

面孔认知中表情的印象操作的有效性

运用促进面孔记忆新的处理策略“表情的印象操作”，研究在笑脸中包含着怎样的信息。研究发现，与平静表情的面孔相比，笑脸是更具优势的表情，在笑脸的表情之中包含着更多促进面孔记忆的信息。     

A Note on the Role of the Propensity Score for Estimating Average Treatment Effects

Hahn [Hahn, J. (1998). On the role of the propensity score in efficient semiparametric estimation of average treatment effects. Econometrica 66:315-331] derived the semiparametric efficiency bounds for estimating the average treatment effect (ATE) and the average treatment effect on the treated (ATET). The variance of ATET depends on whether the propensity score is known or unknown. Hahn attributes this to “dimension reduction.” In this paper, an alternative explanation is given: Knowledge of the propensity score improves upon the estimation of the distribution of the confounding variables.     

浅论缩短反馈时间在中学英语写作教学中的作用

本文通过调查一所普通中学学生对教师英语作文反馈时间的偏好并进行实验研究,利用统计学的描述性统计,独立/相关样本T检验分析方法,作者发现缩短反馈时间确实能够提高学生的英语写作水平,并结合其对教学的启示进行了讨论。     

南京国民政府时期南洋侨教政策负面影响述评

由于历史和现实的缘故，国民政府十分关注海外华侨尤其南洋华侨的教育，形成了比较完善的华侨教育体系，学校和学生数量呈上升趋势，学生素质也不断提高。然而由于国民政府侨教政策自身固有的弊病，给南洋侨教带来了相当的消极作用，限制了南洋侨教事业的进一步发展。     

点击式合同的民事纠纷的管辖及其证据规则

点击式合同是在网络中应用的一种特殊的合同订立形式,由于其订立方式的特殊性,导致在其引起的民事纠纷处理上我国目前的管辖制度和证据规则难以适用,为了适应网络发展和新合同形式的需要,必须制定新的法律规则,以促进网络贸易的发展。     

Diagnostics for dependence within time series extremes

Summary. The analysis of extreme values within a stationary time series entails various assumptions concerning its long- and short-range dependence. We present a range of new diagnostic tools for assessing whether these assumptions are appropriate and for identifying structure within extreme events. These tools are based on tail characteristics of joint survivor functions but can be implemented by using existing estimation methods for extremes of univariate independent and identically distributed variables. Our diagnostic aids are illustrated through theoretical examples, simulation studies and by application to rainfall and exchange rate data. On the basis of these diagnostics we can explain characteristics that are found in the observed extreme events of these series and also gain insight into the properties of events that are more extreme than those observed.