Dynamic inference for non-Markov transition probabilities under random right censoring

The main contribution of this article is the verification of weak convergence of a general non-Markov (NM) state transition probability estimator by Titman, which has not yet been done for any other general NM estimator. A similar theorem is shown for the bootstrap, yielding resampling-based inference methods for statistical functionals. Formulas of the involved covariance functions are presented in detail. Particular applications include the conditional expected length of stay in a specific state, given occupation of another state in the past, and the construction of time-simultaneous confidence bands for the transition probabilities. The expected lengths of stay in a two-sample liver cirrhosis dataset are compared and confidence intervals for their difference are constructed. With borderline significance and in comparison to the placebo group, the treatment group has an elevated expected length of stay in the healthy state given an earlier disease state occupation. In contrast, the Aalen-Johansen (AJ) estimator-based confidence interval, which relies on a Markov assumption, leads to a drastically different conclusion. Also, graphical illustrations of confidence bands for the transition probabilities demonstrate the biasedness of the AJ estimator in this data example. The reliability of these results is assessed in a simulation study.     

Comparison of multiple imputation and two-phase logistic regression to analyse two-phase case–control studies with rich phase 1: a simulation study

Two-phase case–control studies cope with the problem of confounding by obtaining required additional information for a subset (phase 2) of all individuals (phase 1). Nowadays, studies with rich phase 1 data are available where only few unmeasured confounders need to be obtained in phase 2. The extended conditional maximum likelihood (ECML) approach in two-phase logistic regression is a novel method to analyse such data. Alternatively, two-phase case–control studies can be analysed by multiple imputation (MI), where phase 2 information for individuals included in phase 1 is treated as missing. We conducted a simulation of two-phase studies, where we compared the performance of ECML and MI in typical scenarios with rich phase 1. Regarding exposure effect, MI was less biased and more precise than ECML. Furthermore, ECML was sensitive against misspecification of the participation model. We therefore recommend MI to analyse two-phase case–control studies in situations with rich phase 1 data.     

What can we learn from twin studies? A comprehensive evaluation of the equal environments assumption

Twin studies are a major source of information about genetic effects on behavior, but they depend on a controversial assumption known as the equal environments assumption (EEA): that similarity in co-twins’ environments is not predictive of similarity in co-twin outcomes. Although evidence has largely supported the EEA, critics have claimed that environmental similarity has not been measured well, and most studies of the EEA have focused on outcomes related to health and psychology. This article addresses these limitations through (1) a reanalysis of data from the most cited study of the EEA, Loehlin and Nichols (1976), using better measures, and through (2) an analysis of nationally representative twin data from MIDUS using more comprehensive controls on a wider variety of outcomes than previous studies. Results support a middle ground position; it is likely that the EEA is not strictly valid for most outcomes, but the resulting bias is likely modest.     

人性假设与公共行政思想演变

人性假设是一切社会科学的逻辑起点,从人性假设出发审视公共行政思想演变是阐释公共行政发展史的重要视角。以公共行政学科建立为界限,公共行政思想演进历程可分为前公共行政学时期和公共行政学时期。从人性假设出发,可以了解前公共行政学时期在性善论影响下的中国政治与行政思想的内控型特征,在性恶论影响下的西方政治与行政思想的外控型特征,以及公共行政学时期以性恶论为基础的经济人假设、以性善论为基础的社会人假设、以人性善恶二重性为基础的复杂人假设对公共行政思想中管理主义、宪政主义及其二者整合的影响。     

关于环境会计基本假设的探讨

环境基本会计假设是对环境会计核算中无法确定的事项所作的合理推断,是建立环境会计理论与方法的基础。对于环境会计的基本假设,会计理论界有多种看法。本文认为,环境会计作为会计学的一个分支,其基本假设应以传统会计为基础,同时又要有所创新。本文将环境会计的基本假设归纳为6个方面,并论述了环境会计基本假设的基本内容以及与传统会计基本假设的异同。     

科学假说与伪科学歪理邪说的分界

伪科学的一个突出特点是打着发展科学、提出新的科学假说的旗号欺骗群众.科学假说所具有的假设性的特点,也给伪科学留下可乘之机.本文从科学假说和伪科学与科学事实、科学理论、科学检验三方面的关系,分析了二者的本质区别.从三个方面的分析中还可以看出,我们与伪科学的斗争将是长期的.     

Performance of traditional f tests in repeated measures designs under covariance heterogeneity

This study investigates the performance of two traditional F tests, one for main effects and the other for interaction in repeated measures designs under several conditions of covariance heterogeneity. Overall, the test for interaction is more vulnerable than the one for main effects. Distortion in the level of significance is less serious for the case of equal group size.     

Cumulants of random sum distributions

Consider a random variable S being the sum of a number N of independent and identically distributed random variables X_j (j = 1, 2, ...) where the number N is itself a non-negative integer-valued random variable independent of the X_j An explicit expression of the r-th cumulant of S is given in terms of the cumulants of N and X_j, Asymptotic properties of the distribution of S are also discussed.     

认知语境视角下社交语用失误成因分析

跨文化交际的本质是人与人之间的交际,对社交语用失误的解读必须考虑交际参与者的主观能动性和认知能力.在跨文化交际中,若认知心理状态不同的交际者对彼此制约交际的社交文化规约的心理可及程度较低,加上交际的瞬时性和省力原则的作用,说话人对听话人的认知语境假设选择的判断可能与听话人的真实认知语境假设选择不符,使得听话人推理出的说话人交际意图和说话人真实的交际意图不一致,从而导致社交语用失误.