An Asymptotic Analysis of the Logrank Test

Asymptotic expansions for the null distribution of the logrank statistic and its distribution under local proportional hazards alternatives are developed in the case of iid observations. The results, which are derived from the work of Gu (1992) and Taniguchi (1992), are easy to interpret, and provide some theoretical justification for many behavioral characteristics of the logrank test that have been previously observed in simulation studies. We focus primarily upon (i) the inadequacy of the usual normal approximation under treatment group imbalance; and, (ii) the effects of treatment group imbalance on power and sample size calculations. A simple transformation of the logrank statistic is also derived based on results in Konishi (1991) and is found to substantially improve the standard normal approximation to its distribution under the null hypothesis of no survival difference when there is treatment group imbalance. This revised version was published online in July 2006 with corrections to the Cover Date.     

拯救辩证法还是消解辩证法——与田海平、马英林二先生商榷

一个半世纪前,马克思提出要从黑格尔哲学的神秘形式中把"一切辩证法的基本形式"解救出来。一个半世纪后,田海平、马英林二先生在《拯救辩证法:后形而上学时代的思想任务》一文中,重提"拯救辩证法"这一课题,对当代的辩证法研究是一个极大的推动。马克思的哲学研究,不仅有效地拯救了以黑格尔为代表的思辨辩证法,而且卓有成效地创立了合理形态的辩证法。但是,田、马二先生却认为,马克思的工作只是拯救辩证法这一"漫长旅程的开端或开始",而更重要的任务乃是进一步从形而上学的思想谱系与现实运作中"拯救"辩证法,并且认为,这是"后形而上学时代的思想任务"。不难看出,田、马二先生的"拯救辩证法"与马克思的"拯救辩证法"是根本不同的:马克思的拯救辩证法,是剔除神秘主义的思辨形式,救出"一切辩证法的基本形式",其结果是救出了辩证法;而田、马二先生的拯救辩证法,则是只保留辩证法的批判本性,而否定辩证法的形而上的本体论意蕴,从而否定一切辩证法共同具有的"基本形式",其结果是消解了辩证法。     

民国末年四川地区不动产交易中民间契约的法律地位探析

土地经济时代的土地、田产、房屋是社会经济重要组成部分,其物权所有权转移在民国末年极受关注.传统的经济环境下,多方约束的民间契约调节着社会经济关系的矛盾.理性的考量与通融和顺的民治观念构成民国末年物权交易民间契约的一道风景.乡规民约中,处分财产知情权、分割财产表决权、竞买次序优先权等,其折射出的法律价值取向给我们提供了法实践基础的思维空间.     

BSE Risk Assessment as a Basis for Updating French Screening Policy

The current French bovine spongiform encephalopathy (BSE) surveillance system, based on rapid testing of all cattle over 24 months of age and on clinical diagnosis, detects all clinical cases and some preclinical cases of BSE. Several indicators point to a marked shrinkage of the French BSE epidemic in recent years, owing to risk reduction measures. Meat and bone meal, the only known vector of the BSE agent, was banned in feed for all farmed species in November 2000. Thus the surveillance system may be relaxed. The objective of this risk assessment study was to provide information for decisionmakers on the minimum age at which healthy and high-risk cattle now need to be screened with rapid tests. For this purpose, we used the back-calculation method to project the course of the BSE epidemic. We examined the predicted patterns of the number and age distribution of cases of BSE that would be detected by the different existing surveillance streams. Various theoretical sensitivities of rapid tests were explored. Assuming that feed-borne sources of infection no longer exist, and that BSE does not occur spontaneously, our models suggest that it would have been possible to raise the minimum age for rapid tests to 66 months in early 2006, whereas theoretical reasoning, based on the assumption that the total meat and bone meal ban was effective in November 2001, suggests that this age cutoff could only be raised to 48 months in early 2006. These results only apply to cattle born and bred in France. If the situation remains unchanged, the age cutoff could be raised incrementally each year.     

Emergence of entrepreneurial behaviour: The role of age-based self-image

This study introduces an individual’s perception of their entrepreneurial potential in terms of their age (age-based self-image) to complement chronological age as a predictor of entrepreneurial behaviour. The principal hypothesis is that a positive age-based self-image enhances the likelihood of individuals turning their intention to start a business into actual behaviour. The empirical analysis based on data collected on the general adult population of Finland in 2011 and 2012 (n = 672) supports this hypothesis. The analysis further shows that this positive effect is independent of the individual’s chronological age, and it is thus applicable to both age groups that are under-represented in entrepreneurship: ‘youngsters’ and ‘seniors’. Promoting the development of a positive age-based self-image is a prospective policy option for fostering entrepreneurship among younger and older age groups. More in-depth research, especially concerning the antecedents of positive age-based self-image, is required for the effectiveness of such policy interventions.     

跨境电子商务合同履行流程研究

“互联网+外贸”促进了跨境电子商务的蓬勃发展。而跨境电子商务贸易中最重要的环节为合同履行的过程,它是指在跨境电子商务合同商订后,买卖双方需要做的以使整个交易顺利完成的所有工作,其具体流程主要包括买方付款、卖方发货、报检进仓、平台报关和物流配送及信息跟踪。但目前由于我国的跨境电子商务刚刚起步,政策监管体系还不完善,政策支持还未到位,合同履行中第三方支付、物流、检验检疫以及报关纳税等流程都存在诸多问题。因此,针对这些具体问题,需要在现有交易支付平台上建立健全用户核对系统,确保交易安全,还要构建跨境电子商务风险监控和质量追溯体系,并创新海关监管模式,完善申报制度,并尽快建立一套完善的物流整体解决方案来实现物流、海关和商检等环节的快速衔接,进而促进我国跨境电子商务的快速健康发展。     

中世纪哲学的形成:理性与信仰的调和

理性和信仰是人类精神生活的两大要素,在西方哲学的演进过程中,虽然理性的科学精神占了主导,但整个西方哲学始终运动在理性和信仰交织的精神网络上,尤其是中世纪哲学,理性与信仰的交融与调和孕育出的中世纪哲学,它以一种独特的形态延续着西方哲学发展的轨道。对于欧洲中世纪哲学探析和梳理,有助于我们理解和把握西方哲学的基本精神及发展脉络。     

90年代以来中国夫妇年龄差变动趋势及其原因分析

夫妇年龄差的研究是人口学研究的一个重要领域。但目前的研究由于数据来源多样化,得出的结论不尽一致,关于年龄差的变化方向也没有形成定论。为此,本文利用我国三期妇女地位调查数据,对年龄差变动趋势进行分析。结果发现：我国同龄婚配的特点非常稳定,其比例维持在16％～17％之间。中国夫妇年龄差模式自90年代以来,发生了较大的变化,2010年中国传统的＂男高女低＂的婚配模式有所改变,这种＂男高女低＂婚姻明显下降,而＂女高男低＂婚姻明显升高,扣除同龄婚后二者平分秋色。其原因可能与我国出生性别比持续偏高和婚姻观念的转变等因素有关。     

生命周期视角下与收入相关的健康不平等分析——基于组群分析的方法

本文利用中国健康与营养调查数据,从生命周期的视角对与收入相关的健康不平等的年龄特征和变动进行了基于组群分析的实证研究。研究结果表明：与收入相关的健康不平等随着年龄的增长不断扩大：不同年龄段的健康不平等均呈现不断扩大的变动趋势,45岁以上人群的变动幅度要相对大于45岁以下人群;教育、收入和医疗的不平等是与收入相关的健康不平等扩大的主要原因,但是对45岁以下人群健康不平等的影响要大于45岁以上人群;此外,本文还进一步分析了年龄老化对健康不平等变化的影响路径。     

中国人口年龄结构变动对出生率的影响研究

本文利用相关年份的《中国统计年鉴》和人口普查数据,根据粗出生率与总和生育率的关系与特征,构建了人口年龄结构系数及其对粗出生率变动影响的贡献率指标,分析了建国以来人口年龄结构变动对出生率的影响。研究发现：1949—1979年,人口年龄结构变动对出生率的影响很小;1980—1993年,人口年龄结构变动对出生率的影响迅速上升,年龄结构的贡献率增大;1994—2008年,人口年龄结构变动对出生率的影响趋于下降,人口惯性势能在减弱;2009—2011年,受80—90年代出生高峰的影响,人口年龄结构变动对出生率的影响再次凸显,年龄结构的贡献率迅速增大。从年龄别生育率逐年下降的特点,也可以证明近年推动我国人口增长的力量主要是由于年龄结构带来的惯性增长。