On trends and constants in periodic autoregressions

Periodic autoregressions are characterised by autoregressive structures that vary with the season. If a time series is periodically integrated, one needs a seasonally varying differencing filter to remove the stochastic trend. When the periodic regression model contains constants and trends with unrestricted parameters, the data can show diverging seasonal deterministic trends. In this paper we derive explicit expressions for parameter restrictions that result in common deterministic trends under periodic trend stationarity and periodic integration.     

Determinants of Perceived Interfirm Dependence in Industrial Supplier Relations

Studies of industrial buyer-supplier relations mostly focus on structural characteristics of the transactions between parties, and assume a direct relation between these factors and characteristics of the relationships. This paper focuses on the psychological dimension of transaction relations, reflected in perceptions of dependence, from the perspective of an industrial supplier. In the first step of the analysis, three groups of structural determinants of perceived supplier dependence are explored: factors related to goal mediation, factors related to relation-specific assets, and factors related to network embeddedness. After that, the influence of these structural factors and of perceived supplier dependence on the ordering of buyer-supplier relations is investigated. Data come from a study of the micro-electronics assembly industry in the Netherlands. The findings show that sales to a particular buyer as a percentage of the total sales of the supplier and the growth of sales to a particular buyer (two forms of goal mediation) are important determinants of perceived supplier dependence. Human asset specificity is also related to perceived supplier dependence. Network embeddedness variables play only a minor role in explaining perceived supplier and buyer dependence in this study. The data further show that perceived dependence has an effect on the degree of ordering in the relationship, next to structural factors like the extendedness of the relationship beyond the focal transaction and physical asset specificity. The effects of human asset specificity and dedicated assets on ordering are contrary to what was expected on the basis of the literature.     

具体人性——人权与宽容的新维度

简要列出宽容概念的种类,并概述人权与实际(或具体)人性之间的关联以及实质性的相互关系,基于针对人权的进一步区别、历史修正以及人权阐释的发展的评论,勾勒出人权从保护性人权向供人分享和有积极创造性的人权的发展历程,并提出与标准的法定人权相比,供人分享和有积极创造性的人权是对伦理上的真正尊严的主张,是一种道德人的准权利。因此,用“具体人性”和对具体人性的实际描述真正代替仅仅沉湎于人性和人道的相当抽象的观念,这在所有的人权教育中都是最重要的。     

论1807年的现象学的逻辑

在研究黑格尔《精神现象学》的内容时,应该同时研究其体系学的形式。1807年的现象学是建立在诸逻辑基本环节的某种序列的基础上的,而这种序列与黑格尔当时的逻辑学构想是相一致的,并且在现象学内具有一种统一的功能。要弄清这些基本规定之进程,有着诸多困难。在现象学的布局中的修改并没有走到损害现象学之逻辑根基的地步。本文第一章表明,从一开始,黑格尔就提出了这一要求:在非实在的意识的方式与逻辑的环节之间要有一种严格的对应。第二章讨论这些逻辑的环节作为什么进入意识的经验当中,以及它们如何组织意识的经验。第三章具体说明这些逻辑的基本环节的序列及其同意识的诸阶段的对应。文章最后还把一种有关现象学的方法和有关耶拿逻辑学的发展的见解,提出来进行了讨论。     

Homosexual role separation: Implications for analyzing and modeling the spread of HIV

The analysis of the spread of HIV in homosexual populations must be based on knowledge of all factors which promote or inhibit transmission. Recently, data were reported from the Amsterdam cohort study that imply that sexual role separation and the changes therein should be taken into account in analyzing and modeling the spread of HIV. In this paper, a role separation mixing model is described and linked to data from the Amsterdam cohort. The model allows one to study the impact of homosexual role separation on the spread of HIV. The homosexual men are classified into four sexual subgroups based on the preference for: 1) no anal intercourse; 2) anal insertive only; 3) anal receptive only; 4) both insertive and receptive. The analysis accounts for variability and change in homosexual role behavior and loss to follow up. The results support the conjecture that there are large differences between the risks of receptive and insertive anal intercourse, with the latter carrying only minimal risk. The analysis indicates that the spread of HIV is mostly restricted to subgroup 4, the largest and sexually most active subgroup. In this subgroup, the estimated probability of HIV transmission from an infected insertive partner (in subgroup 2 or 4) to a receptive susceptible (in subgroup 4) is between 1 and 5 percent (assuming a closed cohort).     

Birth order effects on young students’ academic achievement

We examine birth order effects on academic achievement for ten-year-old students using data for the entire population of fifth graders in Norway 2007/2008. The analysis thus adds to a thin empirical literature focusing on birth order effects among young children. We find that being firstborn confers a significant advantage in families with two, three and four children. The analysis makes two other contributions. First, we provide evidence that unless mother's age at childbirth is included among the control variables, only small and imprecise birth order effects are revealed in families with low socioeconomic status. Second, we provide some evidence that the birth order effects differ across families with highly educated and less educated mothers, which lend support to the resource dilution model over the confluence model.     

On trends and constants in periodic autoregressions

Periodic autoregressions are characterised by autoregressive structures that vary with the season. If a time series is periodically integrated, one needs a seasonally varying differencing filter to remove the stochastic trend. When the periodic regression model contains constants and trends with unrestricted parameters, the data can show diverging seasonal deterministic trends. In this paper we derive explicit expressions for parameter restrictions that result in common deterministic trends under periodic trend stationarity and periodic integration.     

Comparing two survey methods for estimating maternal and perinatal mortality in rural Cambodia

PURPOSE: We need solid estimates of maternal mortality rates (MMR) to monitor the impact of maternal care programs. Cambodian health authorities and WHO report the MMR in Cambodia at 450 per 100,000 live births. The figure is drawn from surveys where information is obtained by interviewing respondents about the survival of all their adult sisters (sisterhood method). The estimate is statistically imprecise, 95% confidence intervals ranging from 260 to 620/100,000. The MMR estimate is also uncertain due to under-reporting; where 80-90% of women deliver at home maternal fatalities may go undetected especially where mortality is highest, in remote rural areas. The aim of this study was to attain more reliable MMR estimates by using survey methods other than the sisterhood method prior to an intervention targeting obstetric rural emergencies. PROCEDURES: The study was carried out in rural Northwestern Cambodia where access to health services is poor and poverty, endemic diseases, and land mines are endemic. Two survey methods were applied in two separate sectors: a community-based survey gathering data from public sources and a household survey gathering data direct from primary sources. FINDINGS: There was no statistically significant difference between the two survey results for maternal deaths, both types of survey reported mortality rates around the public figure. The household survey reported a significantly higher perinatal mortality rate as compared to the community-based survey, 8.6% versus 5.0%. Also the household survey gave qualitative data important for a better understanding of the many problems faced by mothers giving birth in the remote villages. There are detection failures in both surveys; the failure rate may be as high as 30-40%. PRINCIPLE CONCLUSION: Both survey methods are inaccurate, therefore inappropriate for evaluation of short-term changes of mortality rates. Surveys based on primary informants yield qualitative information about mothers' hardships important for the design of future maternal care interventions.     

从胡文化“汉化”看生态环境的迁移对文化转型的影响

不同文化特质的形成 ,除受政治经济影响外 ,还受特定生态环境的制约。胡汉两大文化体系的差异 ,在很大程度上就是不同生态环境作用的结果。与此相应 ,文化的发展一旦脱离了与自身相适应的环境 ,就势必要出现势能上的劣势 ,并逐渐与异地文化相溶     

Current and Future Problems of Capital Accumulation in the Chinese Pension System

The decree establishing a uniform system of basic pensions for employees in municipal and private enterprises, published by the State Council on 16 July 1997, reflects the Chinese Government's ultimate choice in favour of a partly private funded scheme to cover future pension needs. This article examines the reasons which led to this choice and asks how easy or otherwise it will be to find the capital to finance it. The authors believe that the partly private scheme is more advantageous than other methods and is right for China. Many issues, however, remain the focus of lively debate. In particular, a realistic coordination of individual and group accumulation is needed in order to avoid shortfalls in capital formation and the dangers of inadequate benefit provision. To safeguard the subsistence needs of former workers in state-owned enterprises, a system of equalization at national level is needed, and problems continue over how future pension insurance funds should best be managed.