污染环境造成他人损害的归责原则——基于司法裁判的实证分析

《民法典》（草案）第1229条规定了污染环境造成他人损害的归责问题，根据现行通说和最高人民法院的司法解释，各类污染侵权均一体适用无过错责任，并排除合规抗辩。但这种大一统观念忽略了各类污染行为的内在差异及其社会效果和法律效果的不同，导致无过错责任在司法实践中难以适用于噪声、噪光、电磁辐射等拟制型污染的场合。为保持法典的稳定性与权威性，应当对第1229条的“污染环境造成他人损害”作限缩解释，使之仅涵盖排放污染物质造成损害的场合；排放能量作为“污染的拟制”，由于并未造成环境本身的污染，不符合第1229条的适用条件，应作为一般侵权适用过错责任；同时，应将第294条作为不具有实质规范效力的宣示条款，从而消除环境污染责任与相邻污染侵害可能存在的竞合。     

Estimation procedures for grouped data – a comparative study

Interval-censored data are very common in the reliability and lifetime data analysis. This paper investigates the performance of different estimation procedures for a special type of interval-censored data, i.e. grouped data, from three widely used lifetime distributions. The approaches considered here include the maximum likelihood estimation, the minimum distance estimation based on chi-square criterion, the moment estimation based on imputation (IM) method and an ad hoc estimation procedure. Although IM-based techniques are extensively used recently, we show that this method is not always effective. It is found that the ad hoc estimation procedure is equivalent to the minimum distance estimation with another distance metric and more effective in the simulation. The procedures of different approaches are presented and their performances are investigated by Monte Carlo simulation for various combinations of sample sizes and parameter settings. The numerical results provide guidelines to analyse grouped data for practitioners when they need to choose a good estimation approach.     

Imputation of MĀori Descent for Electoral Calculations in New Zealand

The New Zealand Government Statistician decided that, for electoral purposes, Statistics New Zealand should impute Māori–descent status for individuals not responding Yes or No to theMāori–descent question in the 1996 Census of Population and Dwellings. Imputation provides a sounder basis for calculating electoral populations than the approach used in 1994, when all who had not answered clearly Yes or No in the 1991 Census were effectively allocated to non–Māori descent. For the purposes of imputation, the key variables related to the Māori–descent variable were identified using a statistical technique called CHAID (Chisquared Automatic Interaction Detector). Subgroups were created by cross–classification across five variables—island, iwi, Māori ethnic group, Māori–descent composition of the rest of the household, and age group. Within each subgroup, the proportion who responded Yes or No for Māori descent was used to allocate the remainder to Yes or No. The imputation increased the proportion allocated to Māori descent from 16.0% to 17.4% of the total population. However, the proportion of the population imputed to Māori descent was smaller than the proportion who specified Māori descent originally.     

对移动业务实施价格下限管制的几点建议

本文在对价格下限管制理论概述的基础上,分析了中国移动通信市场实施价格下限管制的必要性以及特殊性(包括管制目的、地区差异性和相关成本数据的缺乏),在借鉴了国外实施价格下限管制的相关经验之后,从业务组合的设计、价格下限的设定、具体实施与审核等方面提出了具有一定可操作性的建议。     

Using data augmentation to correct for non-ignorable non-response when surrogate data are available: an application to the distribution of hourly pay

Summary.  The paper develops a data augmentation method to estimate the distribution function of a variable, which is partially observed, under a non-ignorable missing data mechanism, and where surrogate data are available. An application to the estimation of hourly pay distributions using UK Labour Force Survey data provides the main motivation. In addition to considering a standard parametric data augmentation method, we consider the use of hot deck imputation methods as part of the data augmentation procedure to improve the robustness of the method. The method proposed is compared with standard methods that are based on an ignorable missing data mechanism, both in a simulation study and in the Labour Force Survey application. The focus is on reducing bias in point estimation, but variance estimation using multiple imputation is also considered briefly.     

Survey item nonresponse and its treatment

Summary One of the most salient data problems empirical researchers face is the lack of informative responses in survey data. This contribution briefly surveys the literature on item nonresponse behavior and its determinants before it describes four approaches to address item nonresponse problems: Casewise deletion of observations, weighting, imputation, and model-based procedures. We describe the basic approaches, their strengths and weaknesses and illustrate some of their effects using a simulation study. The paper concludes with some recommendations for the applied researcher. We are grateful to an anonymous referee who provided helpful comments. Also we like to thank Donald B. Rubin for helpful comments and always motivating discussions as well as Ralf Münnich for inspiring discussions about raking procedures.     

Missing time-dependent covariates in human immunodeficiency virus dynamic models

Summary. The study of human immunodeficiency virus dynamics is one of the most important areas in research into acquired immune deficiency syndrome in recent years. Non-linear mixed effects models have been proposed for modelling viral dynamic processes. A challenging problem in the modelling is to identify repeatedly measured (time-dependent), but possibly missing, immunologic or virologic markers (covariates) for viral dynamic parameters. For missing time-dependent covariates in non-linear mixed effects models, the commonly used complete-case, mean imputation and last value carried forward methods may give misleading results. We propose a three-step hierarchical multiple-imputation method, implemented by Gibbs sampling, which imputes the missing data at the individual level but can pool information across individuals. We compare various methods by Monte Carlo simulations and find that the multiple-imputation method proposed performs the best in terms of bias and mean-squared errors in the estimates of covariate coefficients. By applying the favoured multiple-imputation method to clinical data, we conclude that there is a negative correlation between the viral decay rate (a virological response parameter) and CD4 or CD8 cell counts during the treatment; this is counter-intuitive, but biologically interpretable on the basis of findings from other clinical studies. These results may have an important influence on decisions about treatment for acquired immune deficiency syndrome patients.     

问卷分割技术在市场调查中的应用

市场调查中为了实现成本效益、准确性以及速度目标往往会采用较长问卷,本文首先分析了因此可能对数据质量产生的影响,在此基础上提出了分割问卷的思想。重点阐述其设计要点,以及如何利用多重插补方法对缺失数据进行处理。     

国际损害责任归责原则新论

归责原则问题是国际损害责任的核心内容,从国际损害责任归责原则的历史发展和发展趋向等多种角度观察,严格责任并非且不应为国际损害责任唯一的归责原则,未来的归责原则体系应当向多元化方向发展;单一的归责模式是不可取的,建立一种具有弹性的归责体系不仅有助于跨越预防与国际损害责任联系问题之障碍,而且为国际损害责任制度未来的发展也提供了更多的空间与可能性。     

Missing data and small area estimation in the UK Labour Force Survey

Summary.  We apply multivariate shrinkage to estimate local area rates of unemployment and economic inactivity by using UK Labour Force Survey data. The method exploits the similarity of the rates of claiming unemployment benefit and the unemployment rates as defined by the International Labour Organisation. This is done without any distributional assumptions, merely relying on the high correlation of the two rates. The estimation is integrated with a multiple-imputation procedure for missing employment status of subjects in the database (item non-response). The hot deck method that is used in the imputations is adapted to reflect the uncertainty in the model for non-response. The method is motivated as a development (improvement) of the current operational procedure in which the imputed value is a non-stochastic function of the data. An extension of the procedure to subjects who are absent from the database (unit non-response) is proposed.