M-tests in multivariate models

Summary For testing homogeneity in multivariatek sample model, robust tests based onM-estimators are proposed and their asymptoticx ²-distributions are investigated. FurthermoreM-tests in multivariate regression models are discussed.     

银行结构与中小企业融资

本文建立了一个中小企业融资问题的分析框架。文章发现 ,中小企业的非匀质性 (heterogeneity)、贷款抵押和交易成本是影响中小企业从银行获得信贷的三个主要因素 ;缓和信息不对称程度、增加贷款抵押、降低交易成本 ,都将使中小企业得到的信贷增加。进一步 ,在一定的前提假设下 ,文章将中小金融机构引入模型 ,发现引入中小金融机构将使中小企业得到的信贷增加 ,增加社会的总体福利 ;并且在中小金融机构的信息优势、数量和中小企业的融资总额之间存在着正向关系。文章最后按照这一框架的思路 ,对中国的中小企业融资难题进行了分析 ,并提出了相应的政策建议。     

Locally robust contracts for moral hazard

We consider a moral hazard problem in which the principal has a slight uncertainty about how the agent’s actions translate into output. An incentive contract can be made robust against an $ϵ$ amount of uncertainty, at the cost of a loss to the principal on the order of $\sqrt{ϵ}$, by refunding a small fraction of profit to the agent. We show that as $ϵ$ goes to zero, this construction is essentially optimal, in the sense of minimizing the worst-case loss, among all modifications to the contract that do not depend on the details of the environment.     

组织公正、相对剥夺感与知识共享:有调节的中介模型

对374份有效问卷数据进行路径分析,研究了组织公正对知识共享行为的影响,以及个体相对剥夺感和群体相对剥夺感的中介作用与归属需求的调节作用。结果显示:1组织公正对知识共享有正向影响;2个体相对剥夺感和群体相对剥夺感在组织公正对知识共享的影响中均发挥部分中介作用,但两者作用方向相反。组织公正能降低个体相对剥夺感和群体相对剥夺感,个体相对剥夺感的降低能增加员工的知识共享行为,而群体相对剥夺感的降低会减少员工的知识共享行为,且组织公正通过群体相对剥夺感对知识共享的负向影响大于个体相对剥夺感的正向影响;3归属需求对个体相对剥夺感与知识共享、群体相对剥夺感与知识共享的关系均具有增强型调节效应。相比而言,归属需求高的员工体验个体相对剥夺感时进行的知识分享较少,而产生群体相对剥夺感时进行的知识共享较多。     

Biased managers as strategic commitment: The relative profit approach

This paper analyzes a duopolistic model wherein each firm׳s owner can hire a biased manager for strategic reasons. We focus on the situation wherein each firm׳s owner evaluates the performance of her/his manager on the basis of her/his relative profit, which is equal to the weighted sum of her/his absolute profit and the absolute profit of her/his opponent firm. We show that in both price-setting and quantity-setting competitions, the owners of the two private firms employ aggressive managers rather than absolute profit maximizing managers regardless of the degree of importance of each firm׳s relative performance. Furthermore, in both the price competition and the quantity competition, as the degree of importance of each firm׳s relative performance increases, we show that the firms׳ owners tend to hire more aggressive managers when the degree of importance of each firm׳s relative performance is sufficiently low, whereas in both the price competition and the quantity competition, the firms׳ owners tend to hire less aggressive managers otherwise. Thus, in both the price competition and the quantity competition, the type of each firm׳s manager is not monotone with respect to the degree of each firm׳s relative performance. Thus, in both the price competition and the quantity competition, we find that the change in the optimal type of manager hired by each firm is non-monotone against the change of competitiveness in the market with the increase in the degree of importance of each firm׳s relative performance.     

基于Wilcoxon秩和检验的多元非参数控制图

在统计过程控制(SPC)中,对多元数据的监测仍然是一个重要且具有挑战性的问题。当缺乏或有限的关于潜在过程分布的认知时,特别是当过程测量是多变量的时候,非参数控制图在统计过程控制(SPC)中是有用的。文章基于Wilcoxon秩和检验结合广义加权移动平均(GWMA)控制方案来制定图表统计量,得到一个新的多元非参数控制图,用于监测多元数据的位置参数变化。文章的理论和数值研究表明,所提出的控制图能够为任意数据分布位置偏移检测提供令人满意的性能。     

Status-seeking behavior,the evolution of income inequality,and growth

Using an overlapping generations model, this paper investigates the implications of status-seeking behavior, induced by preferences for relative income, for the evolution of income inequality. When average income rises, an individual’s marginal utility of their own income may increase (keeping up with the Joneses, or KUJ), or decrease (running away from the Joneses, or RAJ). It is shown that income inequality is shrinking over time in the KUJ economy, whereas it is expanding in the RAJ economy. We also explore the implications for long-run growth and inequality, in the existence of both KUJ and RAJ agents. I am truly grateful to Koichi Futagami for his encouragement and guidance in writing this paper. I have benefitted from comments by an anonymous referee, Been-Lon Chen, Giacomo Corneo, Akiomi Kitagawa, Kazuo Mino, Kazuhiro Yuki, and seminar participants at Osaka University, the 2006 Japanese Economic Association Autumn Meeting at Osaka City University, the Far Eastern Meeting of Econometric Society 2007 at Taipei, SER Conference 2007 at Singapore, and the European Meeting of Econometric Society 2007 at Budapest. All remaining errors are, of course, my own. The financial support from JSPS Research Fellowships for Young Scientists is greatly acknowledged.     

编组站调度信息对阶段计划的影响及计划调整研究

考虑编组站列车到达时间的不确定性，研究阶段计划解体方案的鲁棒调整方法，以提高阶段计划的鲁棒性。在研究编组站列车到达规律及其对阶段计划编制和执行的影响的基础上，分析通过调整解体方案提高阶段计划鲁棒性的必要性和可行性；由列车解体最早开始时刻、解体最晚开始时刻以及待解时间之问的关系，推导出相邻列车解体顺序调整的判定条件；定义了列车待解时间调整量的概念，给出不同情形下列车待解时间的最大调整量的计算方法；基于解体方案鲁棒调整的概念，提出基于随机模拟和经验公式两种解体方案鲁棒调整评价方法；最后给出解体方案鲁棒调整算法。     

A comparison of importance weights and willingness-to-pay measures derived from choice-based conjoint, constant sum scales and best–worst scaling

We review the measurement of product attribute importance, and find little consensus in definition or measurement methods. We compare four measurement methods: 1) two direct methods whereby respondents report the importance of attributes using best–worst scaling or constant sum scales, and 2) two indirect methods derived from discrete choice experiments. Our comparisons rely on previous findings that choice experiments are externally valid to use as the standard. We find high agreement within direct or indirect methods, but less agreement between direct and indirect methods. Our results also demonstrate that inferences derived from indirect measures appear to be susceptible to context effects related to the particular attributes a researcher chooses to investigate. We discuss implications for current and future research.     

Relative wages, labor specialization and bargaining patterns

The goal of this paper is to study the effects of centralized and decentralized bargaining patterns on wage inequality when there are two different types of labor, skilled and unskilled. We present two models where labor is specialized between firms, that is, there are two types of firms, each one employing one type of labor. We show that the revenue shares of the production factors in each type of firm and the union power are crucial determinants of the relative wage. In contrast, the relative expected wage is the same across models and bargaining patterns.