Estimation of the means of the bivariate normal using moving extreme ranked set sampling with concomitant variable

The estimation of the means of the bivariate normal distribution, based on a sample obtained using a modification of the moving extreme ranked set sampling technique (MERSS) is considered. The modification involves using a concomitant random variable. Nonparametric-type methods as well as the maximum likelihood estimation are considered. The estimators obtained are compared to their counterparts based on simple random sampling (SRS). It appears that the suggested estimators are more efficient. Also, MERSS with concomitant variable is easier to use in practice than the usual ranked set sampling (RSS) with concomitant variable. The issue of robustness of the procedure is addressed. Real trees data set is used for illustration.     

The Impact of Product Returns and Retailer's Service Investment on Manufacturer's Channel Strategies*

We study the distribution channel decision of a manufacturer who considers whether to add an online channel (direct channel) to its brick‐and‐mortar retailer (indirect channel). The retailer faces the opportunity to invest in store assistance to help consumers choose products and thus reduce product returns. Special attention is given to the impact of product returns and retailer's store assistance investment on manufacturer's dual channel decision. We examine conditions under which the manufacturer uses dual channels and how various relevant factors affect its channel decision under two settings, depending on whether the retailer has its own online store or not. When the retailer does not have its online store, we find that (i) the addition of the direct channel raises the wholesale price; (ii) the direct channel addition hurts the retailer if the nonreplacement rate is low; (iii) the manufacturer has a lower incentive to add the direct channel when the retailer's service cost is lower or its returns reduction rate from service investment is higher; and (iv) the manufacturer should treat its own returns handling cost as a key factor in its channel structure decision. In addition, when the retailer operates an online store, we find that the manufacturer may have an incentive to add a direct channel such that both firms own direct channels.     

中美贸易摩擦、全球价值链分工与福利效应

基于全球价值链分工,本文利用2018年中美贸易摩擦加征关税清单、世界投入产出数据库(WIOD)和中美家庭消费支出调查等数据,使用Taylor一阶展开法和考虑消费异质性的Creedy方法测算了中美贸易摩擦给全球价值链参与者带来的福利效应。研究发现:第一,无论基于Taylor一阶展开法还是Creedy方法,本轮贸易摩擦给中美两国自身带来的福利损失最大,且美国受损程度明显高于中国;第二,全球价值链上加拿大、墨西哥等北美自由贸易区(NAFTA)成员以及日本、德国、英国等经济体受中美贸易摩擦影响的福利损失较大;第三,国别责任分解表明中美福利损失主要来源于自身加税行为,而其他绝大多数经济体的损失主要由美国加税引致;第四,收入分配方面,中美贸易摩擦引致的中国福利损失是累退性的,而美国福利受损程度与收入呈现非线性的“倒U型”关系,表明中美贸易摩擦不利于收入分配格局的改善。全球价值链各参与者应秉持人类命运共同体理念,积极主动维护多边贸易规则和国际治理秩序。     

论毛泽东对价值规律认识的演变

毛泽东对价值规律的态度和认识经历了一个演变过程。在新民主主义革命时期,他在指导根据地经济建设的时候自觉遵循价值规律;在社会主义改造完成以后,因为无视价值规律,他发动了大跃进和人民公社化运动,但通过人民公社化运动的惨痛教训,他又认识到价值规律不可违背;在国民经济得到恢复以后,他一方面承认价值规律存在的历史必然性,但在另一方面又企图超越价值规律。     

Marginal Regression for Binary Longitudinal Data in Adaptive Clinical Trials

Abstract.  In an adaptive clinical trial research, it is common to use certain data-dependent design weights to assign individuals to treatments so that more study subjects are assigned to the better treatment. These design weights must also be used for consistent estimation of the treatment effects as well as the effects of the other prognostic factors. In practice, there are however situations where it may be necessary to collect binary responses repeatedly from an individual over a period of time and to obtain consistent estimates for the treatment effect as well as the effects of the other covariates in such a binary longitudinal set up. In this paper, we introduce a binary response-based longitudinal adaptive design for the allocation of individuals to a better treatment and propose a weighted generalized quasi-likelihood approach for the consistent and efficient estimation of the regression parameters including the treatment effects.     

加入WTO后的中国经济及日本的对策

虽然东亚产业分布正从"一极集中"到"多极分散",中国东部沿海也在迅速崛起,但笔者依然反对"中国威胁论",认为中国实行的是"非完全、彻底的"市场化,且沿海地区的迅速发展不能代替说明整个中国的发展。与此同时,加入WTO之后会对中国经济和世界经济产生深远的影响,并将成为日本及其国民真正迈向国际化的契机。日本要想有效地利用好中国的优势,一方面应与中国地方政府合作,支持本地中小企业的对外发展,另一方面必须大力推进内部国际化。     

Pseudo‐likelihood ratio tests for semiparametric multivariate copula model selection

The authors propose pseudo‐likelihood ratio tests for selecting semiparametric multivariate copula models in which the marginal distributions are unspecified, but the copula function is parameterized and can be misspecified. For the comparison of two models, the tests differ depending on whether the two copulas are generalized nonnested or generalized nested. For more than two models, the procedure is built on the reality check test of White (2000). Unlike White (2000), however, the test statistic is automatically standardized for generalized nonnested models (with the benchmark) and ignores generalized nested models asymptotically. The authors illustrate their approach with American insurance claim data.     

物流管理在现代会展业的应用分析

我国经济的持续快速发展和经济全球化趋势为我国会展业发展提供了难得的机遇,本文在对会展物流的定义、特征和会展物流系统的内容阐述之后,针对我国会展物流业的现状,提出了发展现代会展物流的对策措施。     

哈尔滨市人口分布问题研究

从整个市域来看,哈尔滨市人口分布具有不平衡性,为圈层结构。从城乡人口分布来看,市区与市辖市县之间形成了二元结构。在城镇规模结构体系上,表现为不够协调。哈尔滨市的人口分布对在土地利用效益、人居环境和城市的区域影响力等方面都构成了一定影响,因此,改善人口分布状态是哈尔滨市未来人口发展中必须着重解决的问题。     

多维最大值吸引场中分布函数的尾等价问题

本文将[3」中对一维情况的分布函数的尾等价定义推广到多维情况,得到两个多维尾等价的分布函数属于同一最大值吸引场的结论。