存在网络外部性下的两阶段圆周模型

本文分析了存在网络外部性下的两阶段圆周模型。网络外部性的存在使厂商有动机降低产品价格以获得更大的市场份额,模型的子博弈精炼纳什均衡表明消费者剩余和社会净福利水平得到改进,同时行业内产品的差异程度偏少。特别地,在强网络外部性下,垄断结构能使社会净福利最大化。     

网络外部性与产品垄断定价策略研究

当产品存在网络外部性时,垄断厂商在一个较长的时期内如何分阶段提供产品并制定一个合理的价格以获得最大的利润是一个重要问题,因为网络外部性可能会对消费者的预期有着重要的影响,从而影响垄断厂商的定价策略和利润.为了探讨这一问题,本文通过构造一个两阶段的动态模型,分垄断厂商可以在不同的阶段提供同质产品和差异产品两种情形来分析了存在网络外部性条件下垄断厂商的动态价策略.研究表明,若垄断厂商在不同阶段提供同质产品,则第一时段的价格要高于第二时段价格的贴现值;若垄断厂商在第二阶段提供差异产品,则产品的价格会比没有网络外部性的情况下有所降低.     

具有网络外部性特征的企业定价策略研究

随着信息技术的发展,传统经济中普遍采用的单一定价策略采用者正在逐渐减少,尤其在具有网络外部性特征的产业中,更多地采用歧视定价策略.针对具有网络外部性的产业中双寡头垄断厂商的定价策略选择行为,将传统Hotelling模型中外生的定价策略作为内生变量,分析了厂商对单一定价和歧视定价的战略选择.模型的子博弈精炼Nash均衡表明:当网络效应不存在时,厂商或者同时采用单一定价,或者同时采用歧视定价;当网络效应存在时,由于网络效应的影响,厂商选择歧视定价的均衡条件放宽,导致厂商采用歧视定价比单一定价更具有成本优势,从而增强了厂商选择歧视定价的趋向.另一方面,若消费者对产品特征的敏感程度加强,也促使厂商选择歧视定价.     

水平差异产品的内生定价策略选择

本文分析了一个存在定价策略选择下的三阶段Hotelling双头垄断模型,其中厂商可以选择采用单一定价策略或者歧视定价策略。模型的子博弈精炼纳什均衡表明厂商或者同时采用单一定价策略,或者同时采用歧视一价策略。当歧视定价的边际成本相对单一定价的边际成本不太高,或者消费乾注重产品特性差异时,厂商会同时选择歧视定价策略,尽管单一定价下厂商的利润要明显高于歧视定价下的利润;当歧视定价的边际成本相对较高或者消费者不太注重产品特性差异时,单一定价将成为厂商的最优选择。最后本文从社会最优的角度分析比较了两种这价策略下的社会净福利水平。     

歧视性定价下的两阶段水平差异模型

在大多数研究产品水平差异的两阶段Hotelling 模型中, 厂商的选址总是偏离社会最优 结果. 根据消费者总剩余的不同取值分析了当双头垄断厂商采用歧视性策略时的两阶段选址 - 定价模型. 两个厂商在博弈的第一阶段中选址定位, 并在第二阶段制定出相应的歧视价格. 模型的子博弈精炼纳什均衡表明歧视性定价下厂商的选址为社会最优.     

考虑组内网络外部性和消费者多归属行为的网络通信平台定价策略

考虑网络通信平台作为连接通信网络用户(消费者)和增值服务提供商(卖方)的双边平台,除了具有组间网络外部性,还具有较强的组内网络外部性的特征,分别建立了垄断、寡头竞争市场的双边平台定价模型,分析了市场结构和部分消费者的多归属行为对平台定价及其利润的影响。研究表明：双边用户的定价在垄断环境下不受网络外部性的影响,而寡头市场下会随着组内网络外部性的增强而提高;当消费者与平台间的匹配成本高于其组内网络外部性带来的正面效用时,平台对消费者多归属时双边用户的定价总是低于其单归属时的定价。平台利润在垄断情形下与消费者(卖方)之间的组内网络外部性呈现单调递增(减)关系,而寡头竞争情况下完全相反,且平台利润会由于消费者的多归属而减少。     

基于网络外部性的企业技术标准控制策略

研究具有网络外部性特征的市场中,拥有主流技术标准的主导厂商对其技术标准的控 制策略. 结果表明,在从属厂商技术联盟等联合反击行为的影响下,网络外部性的强弱以及厂 商的用户基础规模决定了主导厂商的策略选择. 只有网络外部性较弱而且主导厂商的用户规 模优势较大时,主导厂商才会独占技术标准;当网络外部性较强或者主导厂商的用户基础优势 相对较小时,主导厂商应全面开放或者仅对部分厂商开放技术标准. 若政府强制主导厂商实行 非歧视性的技术标准控制策略,则可能会损害社会福利.     

具有网络外部性特征的企业兼并模式选择

在上游垄断、下游双寡头竞争和上下游均为双寡头竞争的两种市场结构下,基于网络外部性建立了标的企业兼并模式选择模型,分析了被兼并的标的企业以横向兼并和纵向兼并为选择的对策均衡.结论表明,在上游垄断、下游双寡头竞争的市场结构下标的企业兼并模式的选择不受网络外部性的影响,而在上下游均为双寡头竞争的市场结构下网络外部性的强度会影响到标的企业兼并模式的选择.最后,在福利分析的基础上也表明了政府与标的企业在兼并模式选择上存在着直接的利益冲突.     

同质Stackelberg双头垄断结构中跟随厂商的固定费用特许决策研究

有的关于在位厂商创新特许的众多文献,往往假定上游产业为完全竞争结构.但现实中有许多原料市场或能源市场是寡占垄断的.因此,本文基于上游原料供应商具有重要市场势力假设,对下游同质Stackelberg双头垄断结构中跟随厂商(成功创新者)的固定费用特许决策进行了研究.上游的垄断特性,使得下游创新厂商的特许决策与上游厂商的原料供应决策成为一个动态博弈过程,本文利用逆向归纳法求取决策最优解.主要结论是:下游Stackelberg跟随厂商的固定费用特许行为能够提高上游垄断厂商的均衡利润,从而在适当条件下可以推动上游潜在进入者进入.若给定上游独占垄断或双头垄断的市场结构不变,由于下游特许导致原料价格攀升使得特许时的产业利润总是低于无特许时,所以下游跟随厂商不会实施特许;若下游的特许行为能推动上游潜在进入者进入,则可以提高下游跟随厂商的特许激励,从而使其偏好特许一定规模的创新.最后,证明了:与"给定上游独占垄断"相比,"给定上游完全竞争"大幅提高了下游厂商的非显著创新特许激励.     

组内网络外部性对双边市场定价的影响分析

将组内网络效应引入双边市场定价模型中,研究组内网络效应和组间网络效应共同作用下的双边市场定价策略问题,突出分析组内网络效应对双边平台企业定价策略的影响;建立两阶段的定价博弈模型,得到组内网络效应和组间网络效应共同作用下的双边市场竞争价格均衡。研究结果表明,组内网络外部性强度对消费者价格和厂商价格的影响取决于双边用户接入平台后的市场结构,即在双边用户单平台接入市场结构和厂商多平台接入的竞争性瓶颈结构下,组内网络外部性对双边市场定价的影响是不相同的;在这两种市场结构下,双边平台竞争获得的利润水平与组内网络外部性成正比,与组间网络外部性成反比。同时,双边用户的价格在单平台接入和多平台接入的市场结构下的大小关系取决于厂商组内网络外部性的强度。     

供应链的协作供应问题研究

当供应链某活动环节的物资需求量过大时, 一个供应点常常不能提供其全部所需物资. 因此, 实际应用中需要多个供应点共同参与. 针对供应链物资需求的特点, 提出了多点协作供 应的数学模型, 通过引入可行方案的定义, 给出了可行方案存在的判定定理, 以及可行方案的 构造方法. 然而一个可行方案可能包含太多的供应点(太多的供应点有时意味着较高的生产准 备费用) , 因此该方案可能并不实用. 考虑到方案可靠性及费用, 给出了求取优化方案的一个启 发式方法. 最后对模型的系统软件集成进行了简单探讨     

供应链分销系统优化及仿真

研究多个制造商多个分销商组成的分销系统, 综合考虑库存成本、订货成本、运输成本和 缺货成本, 建立了较为全面的分销网络成本模型, 以分销商满足市场需求时的服务水平作为优 化问题的约束条件, 求解成本优化问题. 然后, 给出了求解上述最优订货量的方法, 并用仿真方 法分析了价格参数及订货比例系数对总成本的影响. 结论表明: 随着运价参数b 的降低, 总成 本下降幅度较大; 分销商在地理位置方面的特征, 会影响分销商在不同供应商之间的最优订货 比例, 该比例不是越大越好, 也不是越小越好, 最优比例是居中的某个数值.     

Power,authority and legitimacy

Management, human resources, organization, control, leadership, etc., all seem to be just so many euphemisms for power, and this suggests a discourse of management and organization that calls things by their proper name. This paper on the contrary stresses the need to resolve the concept of ‘power’ itself into more differentiated notions, and proposes that clarification may be derived from distinctions once explicit in the vocabulary of Classical antiquity, but lost in modern European languages. It argues that nothing but confusion in thinking about organizations, management and legitimation can result from the failure to recognize that the phenomena this vocabulary identifies and distinguishes are irreducibly different.     

Criteria for selecting a production control philosophy

Logistic objectives constitute a compromise between having short leadtimes and a low volume of work in progress on the one hand and a high resource loading and due date obligation on the other. Miscellaneous production planning approaches offered today provide different combinations of logistic objectives for satisfying a manufacturing strategy. To combine the strength of the various approaches into a unified system, a new approach based on a dynamic and distributed production planning methodology is proposed. To customize the approach, various analyses and specifications have to be made and for that reason some important characteristics and criteria for analysing production control philosophies will be given.     

The social construction of the meaning of acute stressors: a qualitative study of the personal accounts of police officers using a stress counselling service

The police profession is one in which acute stressors are encountered more frequently than in other occupations. Using the personal accounts of 35 police officers attending an in-house stress counselling clinic, the aim of the present study was to provide a qualitative examination of how the institutional context of policing influenced the ways in which acute stressors signified to individual police officers experiencing felt distress. Using the framework of Rational Emotive Behaviour Therapy as an analytical tool, it is argued that beliefs contributing to the experience of felt distress are related to the way in which policing as both an identity and an activity is constructed through the police organizational culture. Not only do these constructions influence the ways in which officers perceive themselves and their environments, but they also operate at the collective level to 'normalize' some emotional responses and to 'pathologize' others which, it is argued, could impact upon the outcomes of interventions such as stress counselling.     

The moderating role of social support in Karasek's job strain model

This paper examines whether social support is a boundary-determining criterion in the job strain model of Karasek (1979). The particular focus is the extent to which different sources of social support, work overload and task control influence job satisfaction, depersonalization and supervisor assessments of work performance. Hypotheses are tested using prospective survey data from 80 clerical staff in a university setting. Results revealed 3-way interactions among levels of support (supervisor, co-worker, non-work), perceived task control and work overload on levels of work performance and employee adjustment (self-report). After controlling for levels of negative affect in all analyses, there was evidence that high levels of supervisor support mitigated against the negative effects of high strain jobs on levels of job satisfaction and reduced reported levels of depersonalization. Moreover, high levels of non-work support and co-worker support also mitigated against the negative effects of high strain jobs on levels of work performance. The results are discussed in terms of the importance of social support networks both at, and beyond, the work context.     

Job insecurity, coping resources and personality dispositions in occupational strain

This paper presents research on the relationships between the work-related stressor of perceived job insecurity and various indicators of occupational strain, taking into account employees' personality dispositions (trait negative and positive affectivity) and coping resources. Respondents were 222 Australian public servants surveyed during organizational restructuring that involved downsizing and threat to job certainty. The research was formulated within an adaptation of Osipow, Doty, and Spokane's (1985) framework of stress-strain-coping that included the possible direct as well as moderating effects of personality dispositions in reporting occupational strain (Parkes, 1990). Findings from hierarchical regression analyses indicate consistent significant independent effects of personality dispositions, coping resources and perceived job insecurity on various indicators of strain. There was also support for the moderating roles of negative affectivity and self-care in the relation between perceived job insecurity and physical strain. Implications for the role of dispositional factors, especially negative affectivity, and the utility of various coping resources in accounting for occupational strain in times of threatened job security are discussed.     

Job stress, job strain, and psychological withdrawal among Dutch university staff: towards a dualprocess model for the effects of occupational stress

This study examined the antecedents of job strain (emotional exhaustion, health complaints) and withdrawal behaviour (e.g. lowered organizational commitment) among a cross-sectional sample of 131 academic staff members of the law department of a large Dutch university. Conservation of resources theory (Hobfoll, 1989) provided the theoretical background for this study. Strains and withdrawal behaviours were expected to be most prominent among those who reported having few resources and/or who reported high job demands. Structural equation modelling revealed that this was indeed the case. As predicted, differential patterns of effects emerged for job demands and job resources. Analysis of the effects of four job-specific stressors revealed that especially the structural aspects of a staff member's teaching task (e.g. the number of students in their classes) contributed strongly to perceived job demands. Theoretical and practical implications of the study are discussed.     

Dermal Uptake of 18 Dilute Aqueous Chemicals: In Vivo Disappearance‐Method Measures Greatly Exceed In Vitro‐Based Predictions

Average rates of total dermal uptake (K_up) from short‐term (e.g., bathing) contact with dilute aqueous organic chemicals (DAOCs) are typically estimated from steady‐state in vitro diffusion‐cell measures of chemical permeability (K_p) through skin into receptor solution. Widely used (“PCR‐vitro”) methods estimate K_up by applying diffusion theory to increase K_p predictions made by a physico‐chemical regression (PCR) model that was fit to a large set of K_p measures. Here, K_up predictions for 18 DAOCs made by three PCR‐vitro models (EPA, NIOSH, and MH) were compared to previous in vivo measures obtained by methods unlikely to underestimate K_up. A new PCR model fit to all 18 measures is accurate to within approximately threefold (r = 0.91, p < 10^?5), but the PCR‐vitro predictions (r > 0.63) all tend to underestimate the K_up measures by mean factors (UF, and p value for testing UF = 1) of 10 (EPA, p < 10^?6), 11 (NIOSH, p < 10^?8), and 6.2 (MH, p = 0.018). For all three PCR‐vitro models, log(UF) correlates negatively with molecular weight (r² = 0.31 to 0.84, p = 0.017 to < 10^?6) but not with log(vapor pressure) as an additional predictor (p > 0.05), so vapor pressure appears not to explain the significant in vivo/PCR‐vitro discrepancy. Until this discrepancy is explained, careful in vivo measures of K_up should be obtained for more chemicals, the expanded in vivo database should be compared to in vitro‐based predictions, and in vivo data should be considered in assessing aqueous dermal exposure and its uncertainty.