Quality Competition and Social Welfare in Markets with Partial Coverage: New Results*

We use a vertical product differentiation model under partial market coverage to study the social welfare optimum and duopoly equilibrium when convex costs of quality provision are either fixed or variable in terms of production. We show the following new results. First, under fixed costs, the social planner charges a uniform price for the single variant that just covers costs of quality provision. Like the duopoly equilibrium, this socially optimal pricing entails a partially uncovered market, but a smaller share of the market is served compared with the duopoly equilibrium. Second, for the variable cost case, it is socially optimal to provide both high‐ and low‐quality variants, but market shares need not be equal. This differs from the result in fully covered markets. Third, in the duopoly equilibrium, the quality spread is too wide under variable costs relative to the social optimum. Under fixed costs, the duopoly produces two variants, but quality is too low relative to the social optimum, which has only one variant.     

Strategic alliances and internationalisation in the aircraft manufacturing industry

Based on an indicator measuring the technological level of aircraft, this paper shows that in the aircraft industry, firms are obliged to deal not only with high technological barriers, but growing financial and market barriers, too. In order to reduce these, a complex network of relationships has developed over time. This network involves both main firms belonging to the world oligopoly and firms capable of offering specialised technology and/or a potential broadening of the market. The result is a worldwide production organisation. This paper highlights the fact that the aircraft industry is undergoing a global reorganisation featuring an integration process where six groups (two in Europe and four in the United States) have come to the fore. In the future, it will be possible to imagine new forms of co-operation between the emerging European and American groups.     

Heterogeneity and Share Contracting in Medical Group Practices

This paper offers an empirical analysis of the relationship between income sharing rules and physician heterogeneity in medical group practices.The economies to group formation associated with risk–sharing, mutual monitoring,and internal referral are served by sharing at least a portion of group income equally. Sharing group income equally is problematic, however, when group members differ in their contribution to group income. Member contributions to group income may differ because of differences in ability, effort, or the price of services across specialty fields. The analysis below is addressed to the question of how income sharing rules in physician groups are affected by variation in member contributions. The analysis finds evidence that heterogeneity in member contributions to group income limits the use of equal income sharing rules in multispecialty groups relative to single specialty groups, and large groups relative to small groups. Nevertheless, 65% of all groups in the survey share at least a pn of group income equally, which broadly suggests that the joint surplus enhancement from risk sharing, mutual monitoring, and internal referral are sufficient to overcome the incentive problems of such rules     

基于M／N检测的高距离分辨率信号的速度补偿

本文介绍了进步频率高距离分辨率信号，分析了运动速度对该高距离分辨率信号的影响，提出了基于多散射中心联合检测（Ｍ／Ｎ检测）的速度环路补偿方案。该方案使用多距离单元的联合检测完成高距离分辨率信号的最佳速率补偿，同时进一步降低目标的虚警概率，提高了目标的发现概率。     

基于制约理论的成本管理模式研究

环境的变化要求相应的成本管理模式发生变革。本文首先分析了环境变化对企业成本管理的影响,之后对作业成本法的管理思想的前提假设进行分析,指出它对于现代企业成本管理的局限性及其产生这些局限性的主要原因。最后,在分析制约理论核心原理的基础上,提出了一种基于制约理论的成本管理模式,试图为研究适应现代企业的成本管理模式提供新的思路。     

北京市房地产业发展的现状、问题与对策

本文在对北京市房地产业现状进行总体分析的基础上,针对其存在的主要问题提出了在新一轮宏观调控下的发展对策.     

国有企业“债转股”政策:功能缺陷与制度依赖——项基于国有企业“债转股”政策跟踪调查的研究

伴随着我国经济体制改革向纵深发展,国有企业负债比率过高的问题更加突出显示出来。为了解决这个问题,我国实施了“债转股”政策。本文讨论四个命题:(1)国有企业是负债比率过高还是收益率过低;(2)“债转股”政策究竟是使国有企业“财务解困”还是“体制解困”;(3)“债转股”政策究竟是转移金融风险还是化解金融风险;(4)资产管理公司为国有企业和国有商业银行解困,将来谁为资产管理公司解困。本文认为“债转股”政策设计存在功能缺陷与制度依赖。国有企业“债转股”政策的成功依赖于国有企业(商业银行)现代企业制度的建立与完善。     

企业并购活动中目标企业选择的层次分析评估研究

企业并购是企业进行资本扩张、促进企业间存量资源合理统流动的重要途径。对企业并购中的目标企企的选择、价值评估进行研究，构建我国企业并前过程中目标企业选择的评价指标体系，运用AHP法对目标企业选择进行定量化评估，将有利于企业通过并购后，实现资源的最优配置．保证企业经营机制协调、有效地运行。     

基于Agent的物流配送决策支持系统研究

物流配送是一个涉及多种影响因素的综合性复杂问题。本文探讨了基于Agent(智能体技术)的物流配送决策支持系统设计，在该系统中的智能体模型中引入学习机制，初步建立了一个具有专家系统特点、可以不断进化的物流配送决策支持系统。     

Robustness issues in multilevel regression analysis

A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood.