Demographic change, macroeconomic conditions, and the murder rate: The case of the United States, 1934–2006

Fluctuations in aggregate crime rates contrary to recent shifts in the age distribution of the U.S. population have cast doubt on the predictive power of the age–crime hypothesis. By examining a longer time horizon, back to the early 1930s, we show that the percentage of the young population is a robust predictor of the observed large swings in the U.S. murder rate over time. However, changes in the misery index—the sum of the inflation and unemployment rates—significantly contribute to explaining changes in the murder rate. This applies, in particular, to those changes that are at odds with the long-run trend of the U.S. age distribution, such as the decline in the murder rate in the latter part of the 1970s or its increase starting around the middle of the 1980s.     

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.     

皮亚杰“儿童自我中心主义”概念评析

在皮亚杰的发生认识论学说中,“儿童自我中心”概念具有非常重要的意义。“儿童自我中心主义”表现在两个方面,即理智的自我中心和社会的自我中心。同时也表现在儿童心理发展的两个不同阶段,即感知-运动阶段和前运算阶段。皮亚杰指出:话动缺乏协调、主客体没有分化是心理上的自我中心状态的根源。儿童理智上的和社会的自我中心都是随着动作的逐渐协调而消逝的。如果仅从个体心理的基础来看,皮亚杰对儿童自我中心状态的根源的分析,以及他所指出的去除自我中心的途径,是基本正确的。但从社会心理机制的角度看,则存在一些明显的局限:明显的认知中心论,混淆了主客体关系与主体间关系,忽略了符号功能与摆脱社会的自我中心状态的内在联系。     

The duration of unemployment in Russia

This paper uses longitudinal survey data to assess factors affecting the duration of unemployment in Russia. We examine four types of marginalised labour force participants, according to ILO guidelines and survey responses, and we estimate duration models for each type. It turns out that the sets of characteristics with the strongest effects on the duration are remarkably similar across the different unemployment definitions and model specifications. Therefore, despite the formidable practical measurement problems, problematic groups of individuals can actually be identified. Received: 27 January 1999/Accepted: 27 January 2000     

尉犁地名和柔然源流考

“尉犁”(包括天山北麓的“于娄”、“于赖”)地名源于(J)yrgir部落之名。“柔然”(虫柔蠕,蠕蠕,芮芮,茹茹)、“於尼讙”、“预龙”、“诸洛固”等部落联合体(政权)或部落名是(J)yrgir的不同音译形式。汉宣帝时该部曾移居焉耆及尉犁等地。相对稳定的社会环境,为该部的发展奠定了基础。在汉地先进的铁制农具、兵器、相关的制度文化以及塔里木盆地土著印欧语居民文化的影响下,亦加快了其社会发展进程。这是该部在两汉以后能得以崛起的重要原因。柔然是突厥语族群中最早信仰佛教的部落,柔然汗国还使用汉语年号,表明该部虽远在西域,却受到了汉文化的深刻影响。     

Considerations on group-wise identical designs for linear mixed models

We consider a general class of mixed models, where the individual parameter vector is composed of a linear function of the population parameter vector plus an individual random effects vector. The linear function can vary for the different individuals. We show that the search for optimal designs for the estimation of the population parameter vector can be restricted to the class of group-wise identical designs, i.e., for each of the groups defined by the different linear functions only one individual elementary design has to be optimized. A way to apply the result to non-linear mixed models is described.     

Optimal discrimination designs for exponential regression models

We investigate optimal designs for discriminating between exponential regression models of different complexity, which are widely used in the biological sciences; see, e.g., Landaw [1995. Robust sampling designs for compartmental models under large prior eigenvalue uncertainties. Math. Comput. Biomed. Appl. 181–187] or Gibaldi and Perrier [1982. Pharmacokinetics. Marcel Dekker, New York]. We discuss different approaches for the construction of appropriate optimality criteria, and find sharper upper bounds on the number of support points of locally optimal discrimination designs than those given by Caratheodory's Theorem. These results greatly facilitate the numerical construction of optimal designs. Various examples of optimal designs are then presented and compared to different other designs. Moreover, to protect the experiment against misspecifications of the nonlinear model parameters, we adapt the design criteria such that the resulting designs are robust with respect to such misspecifications and, again, provide several examples, which demonstrate the advantages of our approach.     

Unemployment Insurance and Underemployment

Should unemployment insurance (UI) systems provide coverage for underemployed job seekers? Based on a statistical analysis of Norwegian unemployment spells, we conclude that the answer to this question is yes. Allowing insured job seekers to retain partial UI benefits during periods of insufficient part‐time work not only reduces UI expenditures during the part‐time work period, but it also unambiguously reduces the time until a regular self‐supporting job is found. Probable explanations are that even small temporary part‐time jobs provide access to useful vacancy information and that such jobs are used by employers as a screening device when hiring from the unemployment pool.     

后现象学思想解惑--唐·伊德技术哲学的实用主义与解释学维度

用胡塞尔先验现象学的立场来理解作为技术哲学的后现象学,这是对唐·伊德思想的一种误解。由于在悬置和变更等基本概念上与胡塞尔现象学出入甚大,后现象学只能算是一种修正主义的现象学;在哲学观和技术观上,后现象学更多地是汲取了杜威实用主义的观点;利科的解释学及对文本概念的广义理解,决定了后现象学必然是一种以探究人工物的意义为旨归的物的解释学。在理解伊德技术哲学时,实用主义和解释学是两个重要、但被忽略的维度。     

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.