“民工荒”现象成因及对策分析

从去年下半年开始出现的“民工荒”打破了我国劳动力“无限供给”的神话,对我国未来经济增长产生了不容忽视的影响。本文对“民工荒”之所以出现作了原因分析,认为当前宏观经济形势和新的二元社会结构是导致“民工荒”的深层次原因,并对此提出了相应的对策。     

A class of saturated row–column designs

A new class of row–column designs is proposed. These designs are saturated in terms of eliminating two-way heterogeneity with an additive model. The (m,s)-criterion is used to select optimal designs. It turns out that all (m,s)-optimal designs are binary. Square (m,s)-optimal designs are constructed and they are treatment-connected. Thus, all treatment contrasts are estimable regardless of the row and column effects.     

On the Breslow–Holubkov estimator

Breslow and Holubkov (J Roy Stat Soc B 59:447–461 1997a) developed semiparametric maximum likelihood estimation for two-phase studies with a case–control first phase under a logistic regression model and noted that, apart for the overall intercept term, it was the same as the semiparametric estimator for two-phase studies with a prospective first phase developed in Scott and Wild (Biometrica 84:57–71 1997). In this paper we extend the Breslow–Holubkov result to general binary regression models and show that it has a very simple relationship with its prospective first-phase counterpart. We also explore why the design of the first phase only affects the intercept of a logistic model, simplify the calculation of standard errors, establish the semiparametric efficiency of the Breslow–Holubkov estimator and derive its asymptotic distribution in the general case.     

Improved approaches to interval estimation of effective doses for a logistic dose-response curve

Asymptotic confidence (delta) intervals and intervals based upon the use of Fieller's theorem are alternative methods for constructing intervals for the <$>gamma<$>% effective doses (ED<$>_gamma<$>). Sitter and Wu (1993) provided a comparison of the two approaches for the ED<$>_{50}<$>, for the case in which a logistic dose response curve is assumed. They showed that the Fieller intervals are generally superior. In this paper, we introduce two new families of intervals, both of which include the delta and Fieller intervals as special cases. In addition we consider interval estimation of the ED<$>_{90}<$> as well as the ED<$>_{50}<$>. We provide a comparison of the various methods for the problem of constructing a confidence interval for the ED<$>_gamma<$>.     

Generalized neighbor designs with block size 3

A generalized neighbor design relaxes the equality condition on the number of times two treatments as neighbors in the design. In this article, we have considered the construction of some classes of generalized neighbor designs with block size k=3 by using the method of cyclic shifts. The distinguishing feature of this construction method is that the properties of a design can easily be obtained from the sets of shifts instead of constructing the actual blocks of the design. A catalog of generalized neighbor designs with block size k=3 is compiled for v∈{5,6,…,18} treatments and for different replications. We provide the reader with a simpler method of construction, and in general the catalog that gives an open choice to the experimenter for selecting any class of neighbor designs.     

Logistic regression and other discrete data models for serially correlated observations

Summary We consider the analysis of discrete serially correlated data in the presence of time dependent covariates. If the interest is to relate the covariates to the marginal distribution of the data, Markov chains are an obvious tool to consider, but their use is complicated by the fact that they are expressed in terms of transitional rather than marginal probabilities. We show how to parametrize the transition matrix in a suitable way so that interpretation is as desired. The focus is on binary and Poisson data, but the methodology can be adopted also with other discrete data distributions.     

二元(二阶)线性递归关系解的周期性的简便判别法

本文给出了判别二元(二阶)线性递归关系解的周期的简便方法。     

Bayesian analysis of agricultural field experiments

The paper describes Bayesian analysis for agricultural field experiments, a topic that has received very little previous attention, despite a vast frequentist literature. Adoption of the Bayesian paradigm simplifies the interpretation of the results, especially in ranking and selection. Also, complex formulations can be analysed with comparative ease, by using Markov chain Monte Carlo methods. A key ingredient in the approach is the need for spatial representations of the unobserved fertility patterns. This is discussed in detail. Problems caused by outliers and by jumps in fertility are tackled via hierarchical t formulations that may find use in other contexts. The paper includes three analyses of variety trials for yield and one example involving binary data; none is entirely straightforward. Some comparisons with frequentist analyses are made.     

章法结构及其哲学义涵

章法所探讨的是,篇章之条理,亦即连句成节(句群)、连节成段、连段成篇的逻辑组织.这种逻辑组织或条理,对应于宇宙人生规律,完全根源于人心之理,是人人与生俱有的.所以大多数的人,包括作者本身,对它的存在虽大都不自觉,却会自然地反映在他们的思考或作品之中.这种反映出来的逻辑组织或条理,由于对应于宇宙人生规律,就必然与探讨宇宙人生规律的哲学与科学有密切之关系.本文即择要就章法之类型、规律与转化(包括移位与转位)与"多、二、一(0)"的结构等,从中国哲学的逻辑结构中,以<周易>与<老子>两种典籍为主,一一作其哲学义涵之考辨,为章法之所以是"客观的存在",而定位为篇章之逻辑条理或结构,提出有力的证明与依据.     

双重二元分割:单位制变革中的城市劳动力市场

劳动力市场分割是世界各国的普遍现象,是对于劳动力市场非完全竞争的另一种表述。我国城市劳动力市场是在“单位制”变革的背景下形成的,在宏观上表现为体制内劳动力市场与体制外劳动力市场的二元分割。其中体制内劳动力市场与体制外劳动力市场又分别存在着二元分割,因此呈现出双重二元分割的状态。劳动力市场的双重二元分割在现实当中表现为我国劳动力市场中独特的就业模式和收入分配模式。这种劳动力市场的分割状态会随着“单位制”持续变革发生动态的调整和演变,其目标取向是规范统一的劳动力市场。