Estimation of variance in bivariate normal distribution after the preliminary test of homogeneity

A preliminary test estimator of variance in the bivariate normal distribution is proposed after the Pitman–Morgan test of homogeneity of two variances. The bias and mean square error of the estimator are derived. The relative efficiency (RE) of the preliminary test estimator is studied. Computations and 3D graphs of RE for different parameters are analyzed. In order to get the maximum RE, recommendations of the significance level for the preliminary test are given for various sample sizes by using the max–min criterion.     

"Chain pooling" model selection for two-level fixed effects factorial experiments

As many as three iterated statistical model deletion procedures are considered for an experiment.Population model coeff cients were chosen to simulate a saturated 2⁴experiment having an unfavorable distribution of parameter values.Using random number studies, three model selection strategies were developed, namely, (1) a strategy to be used in anticipation of large coefficients of variation (neighborhood of 65 percent), (2) strategy to be used in anticipation of small coefficients of variation (4 percent or less), and (3) a security regret strategy to be used in the absence of such prior knowledge     

养老保险统筹层次收入再分配理论研究

基础养老保险全国统筹层次的实施,具有养老保险给付收入再分配性质和功能。文章提出养老保险统筹层次收入再分配理论架构,包括养老保险统筹层次收入再分配功能;养老保险统筹层次收入再分配生存公平和劳动公平;养老保险统筹层次收入差距与收入再分配系数联动;养老保险统筹给付适度水平检验,等等。这四个相互关联的理论要素,构成了养老保险统筹层次收入再分配理论框架。养老保险统筹层次的收入再分配理论,是养老保险统筹层次选择、养老保险统筹模式设计的基本理论依据,也是政府部门制定养老保险统筹方案的重要逻辑线路和政策依据。     

Equal access to income and union dissolution among mainland Puerto Ricans

This study investigates the implications for union stability of different methods for providing access to income in cohabiting and marital unions among mainland Puerto Ricans. Using the Puerto Rican Maternal and Infant Health Study (N = 836), we show that union dissolution is associated with both union type and type of method. The relatively high rate of union dissolution among cohabiters is explained partially by their lower likelihood of organizing access to income under an equality principle through income pooling. Cohabiting unions that follow the equality principle, however, are as stable as marital unions that follow the equality principle. These patterns are interpreted in terms of the role of economic equality in solidifying socioemotional bonds.     

企业合并会计处理方法的探讨

企业合并是指两个或两个以上的企业通过一定方式,组成一个新的企业的行为。《国际会计准则》第22号中规定,企业合并根据合并的性质采用购买法或股权联合法进行会计处理。在美国的会计发展史上,购买法和股权联合法伴随着并购浪潮而产生,而且股权联合法一度成为选择的重点,但是美国财务会计准则委员会(FASB)则于1999年在修订的16号会计原则委员会意见书(APBopinion)中,正式取消了股权联合法。因此购买法在美国成为企业合并的唯一方法,随之我国也出现了购买法和股权联合法之争,争论的焦点在于我国是否采纳联合法。本文认为我国应根据两种方法的特点和我国的具体会计环境确定,而不能简单地模仿美国否定股权联合法。     

考虑多种安全库存策略的选址-库存问题研究

考虑多种安全设置策略的物流网络的选址-库存问题,不仅是选址、订货、运输和库存的集成优化,还需要考虑多种不同的安全库存设置和转运策略。因此,本文深入讨论了二级物流网络中的六种安全库存设置策略,构建了六种考虑不同安全库存设置的选址-库存模型。在考虑集中设置安全库存时,集中安全库存需要通过转载运输实现,因此需要将转载运输成本引入选址-库存模型之中,使新的选址-库存模型更加科学合理。另外,针对六种新的选址-库存模型,提出了基于个体成本差异分配的遗传算法,迭代搜索选址、分配、库存设置策略的优化组合。最后,通过数据实验验证了模型的有效性：（1）安全库存与转载运输之间存在此消彼长的背反关系;（2）安全库存设置和转载运输策略对总成本的影响取决于两种费率权重情况。本文的研究可以为二级物流网络的选址、订货和安全库存策略集成优化决策提供参考依据。     

Pooling operators with the marginalization property

In this paper, we consider the problem of combining a number of opinions which have been expressed as probability measures P₁, …, P_n, over some space. It is shown that a pooling formula which has the marginalization property of McConway (1981) must be of the form T = Σⁿ_i=₁W_i P_i + (1 - Σⁿ_i =₁W_i)Q, where Q is an arbitrary measure and W₁, …, W_n ϵ [—1,1] are weights such that| Σ_J Σ _j w_j | ≤ 1 for every subset J of {1, …, n}. If, in addition, T is required to preserve the independence of arbitrary events A and B whenever these events are independent under each P_i, then either T = P_i for some 1 ≤ i ≤ n or T = Q, in which case Q takes values in {0, l}.     

Household expenditure patterns and resource pooling: evidence of changes in post-apartheid South Africa

The primary aim of this paper is to examine whether resources accruing to different members of the household and from different sources have differential impacts on household expenditure patterns. The issue is of considerable policy interest for, if the identity of the income recipient does matter in the household’s expenditure decisions, then it indicates the usefulness of targeting income assistance at particular members of the household. The South African evidence is generally supportive of the hypothesis of resource pooling by the income earners in their spending decisions on food, clothing and energy. The results of this paper have been placed in the wider context of social, political and economic developments following the end of apartheid that have caused significant changes in the nature of resource inflow and in the balance of power in decision making within the South African household. The results are indicative of improvements in the standard of living of the majority of South Africans following the end of apartheid.

A two-stage procedure to pool information across quantile levels in linear quantile regression

In linear quantile regression, the regression coefficients for different quantiles are typically estimated separately. Efforts to improve the efficiency of estimators are often based on assumptions of commonality among the slope coefficients. We propose instead a two-stage procedure whereby the regression coefficients are first estimated separately and then smoothed over quantile level. Due to the strong correlation between coefficient estimates at nearby quantile levels, existing bandwidth selectors will pick bandwidths that are too small. To remedy this, we use 10-fold cross-validation to determine a common bandwidth inflation factor for smoothing the intercept as well as slope estimates. Simulation results suggest that the proposed method is effective in pooling information across quantile levels, resulting in estimates that are typically more efficient than the separately obtained estimates and the interquantile shrinkage estimates derived using a fused penalty function. The usefulness of the proposed method is demonstrated in a real data example.     

服务水平约束下的建筑安装行业多仓库联合库存系统模型研究

本文针对建筑安装行业库存管理的特点,对其不同地点的多个仓库的库存方式进行综合分析,建立了服务水平约束下的建筑安装行业多仓库联合库存系统模型,给出了相应的数学模型与算法。通过算例验证表明,服务水平约束下的建筑安装行业多仓库联合库存系统模型可以有效降低建设项目的库存成本,对增加企业利润有着十分重要的现实意义。