The Aggregate Relation between Profits and Concentration is Consistent with Cournot Behavior

An important and controversial stylized fact inindustrial organization is the positive correlationbetween industry profit and concentration. Oneinterpretation of this finding is based on thetheories of Chamberlin and Stigler, which imply thatconcentrated industries facilitate collusion. Butnon-cooperative profit maximizing behavior can alsogenerate a positive correlation. This paperpresents an equilibrium model of oligopoly whichnests the behavioral assumptions of Bertrand,Cournot, and Chamberlin. Simulations of the modelunder the Cournot assumption yield regressioncoefficients for the profits-concentration relationthat are very close to the estimated coefficients inthe literature.     

中国制造业集中及其国际化比较

本文采用第三次全国工业普查521个制造行业近60万个企业的系统数据，深入考察了中国制造业的市场集中状况，行业特征及其国际比较，分析结果表明，中国绝大多数制造业行业的集中度都非常低，产业组织结构高度分散，因此，如何按照分类指导、区域对待的原则，实行分类调控和引导，以有效提高制造业特别是规模效益显著行业的集中度，将是当前产业组织政策亟待解决的一个重要课题。     

短期电力供需预警系统及应用

将研究宏观经济运行的预测预警理论引入到电力供需形势分析，针对电力供需分析的特点，设计了电力供需预警系统的指标体系，并以湖北电网为例，说明了预测预警理论对电力供需形势分析的有效性，在一定程度上反映了湖北电网电力供需形势的发展变化。算例结果表明：先行合成指数超前一致合成指数1～2个月，相关部门可以据此提前采取应对措施，缓和电力供需紧张形势。     

中国煤电能源供应链风险关系及风险评价测度研究

煤电能源供应链的风险管理问题是保障中国能源安全的重要基石。本文针对中国煤电能源供应链的绩效和风险管理,研究了煤电能源供应链风险管理的风险评价测度问题。基于供应链部门关系的界定,利用价值驱动树方法对风险源传递关系进行梳理,构建中国煤电能源供应链指标体系（C －ES-CRMIS）。通过社会问卷调查的方式收集样本,进行主成分分析,建立结构方程模型（SEM ）;为测量指标权重,对风险因子载荷分析、二级因子路径系数进行计算;基于指标相关性的指标权重确定方法（CRIT-IC ）,得到煤炭供应链风险评价测度模型（C－ESCRE ）。结果表明：现阶段,中国煤电能源供应链的主要风险源为政策风险、意外灾害和市场需求风险。节点企业可根据测度模型,对其供应链风险进行评价分析。最后进行了案例分析,以期为政府宏观调控、供应链协同管理以及企业内部控制提供参考。     

Supply function equilibria with capacity constraints and pivotal suppliers

The concept of a supply function equilibrium (SFE) has been widely used to model generators' bidding behavior and market power issues in wholesale electricity markets. Observers of electricity markets have noted how generation capacity constraints may contribute to market power of generation firms. If a generation firm's rivals are capacity constrained then the firm may be pivotal; that is, the firm could substantially raise the market price by unilaterally withholding output. However the SFE literature has not fully considered the impact of capacity constraints and pivotal firms on equilibrium predictions. We characterize the set of symmetric supply function equilibria for uniform-price auctions when firms are capacity constrained and show that this set is increasing as capacity per firm rises. We provide conditions under which asymmetric equilibria exist and characterize these equilibria. In addition, we compare results for uniform-price auctions to those for discriminatory auctions, and we compare our SFE predictions to equilibrium predictions of models in which bidders are constrained to bid on discrete units of output.     

Multilateral Vertical Contracting with an Alternative Supply: The Welfare Effects of a Ban on Price Discrimination

Rey and Tirole [Handbook of Industrial Organization. Amsterdam: Elsevier (2005)] considered a model in which a monopolist sells to downstream firms using nonlinear contracts. They showed that banning price discrimination fully restores the supplier’s ability to leverage its monopoly power by enabling it to commit not to offer side discounts. I show that the situation changes when the supplier competes against a fringe of less efficient rivals rather than being a monopolist. Then banning price discrimination may cause per-unit prices to fall and welfare to increase. The dominant supplier can take advantage of a strategic bargaining effect: reducing the per-unit price makes the outside option of buying from the fringe less profitable, allowing the dominant supplier to extract more bargaining surplus through the fixed fee.     

2011年1季度全国电力供需形势分析及2季度预测

分析了2011年1季度的宏观经济运行情况和电力需求、电力供应、电力供需形势,预测了2季度的宏观经济走势和全国及各区域电力需求和电力供应形势,对局部地区可能出现的电力供需紧张状况提出了一些对策建议。     

Supply chain scheduling and coordination with dual delivery modes and inventory storage cost

We study a two-echelon supply chain scheduling problem in which a manufacturer acquires supplies from an upstream supplier and processes orders from the downstream retailers. The supply chain sells a single short-life product in a single season. We consider the scenario where the manufacturer can only accept some of the orders from the retailers due to its supplier's common production time window and its own two common production and delivery time windows. The upstream supplier processes materials and delivers the semi-finished products to the manufacturer within its time window. Then the manufacturer further processes these products to produce finished products and delivers them to the retailers within its two time windows, where one window is for production and normal delivery, and the other is for production and express delivery. Having to store the materials before processing them, the supplier incurs a storage cost, which depends on the order size and storage time. The manufacturer pays the transportation cost for delivering the finished products to the retailers. Due to double marginalization, the performance of the supply chain is sub-optimal. We model the supply chain problem as a flow shop scheduling problem with multiple common time windows. We derive some dominance properties and establish some theorems that help solve the sequencing problems for the orders and eliminate the idle time among the orders. Based on these results, we develop fast pseudo-polynomial dynamic algorithms to optimally solve the problem. We prove that the problem is NP-hard in the ordinary sense only. We develop two practically relevant and robust methods for the supply chain to achieve optimal profit-making performance through channel coordination.     

Supply network capacity planning for semiconductor manufacturing with uncertain demand and correlation in demand considerations

A semiconductor supply network involves many expensive steps, which have to be executed to serve global markets. The complexity of global capacity planning combined with the large capital expenditures to increase factory capacity makes it important to incorporate optimization methodologies for cost reduction and long-term planning. The typical view of a semiconductor supply network consists of layers for wafer fab, sort, assembly, test and demand centers. We present a two-stage stochastic integer-programming formulation to model a semiconductor supply network. The model makes strategic capacity decisions, (i.e., build factories or outsource) while accounting for the uncertainties in demand for multiple products. We use the model not only to analyze how variability in demand affects the make/buy decisions but also to investigate how the correlation between demands of different products affects these strategic decisions. Finally, we demonstrate the value of incorporating demand uncertainty into a decision-making scheme.     

Supply chain environmental investments in dynamic industries: Comparing investment and performance differences with static industries

Research linking investments in environmental practices to firm performance has matured over the past years. However, empirical research is still ambiguous on how and whether investments in environmental practices improve a plant's performance. We believe that contingency factors, especially the industry in which plants act has a significant role in the success of environmental investments. Using empirical data collected across a wide range of industries our results indicate that plants competing in dynamic industries such as apparel do on average invest less in supply chain environmental practices compared to plants in static industries. In addition, these environmental investments do not significantly improve operational performance in dynamic industries in terms of cost, quality, delivery and flexibility. However, in static industries environmental investments do significantly improve a plant's operational performance in terms of cost, quality and flexibility.     

基于货币供需变动的我国货币政策有效性研究

货币政策的有效性问题一直受到我国学术界的关注,特别是近年来中央银行针对愈演愈烈的通货膨胀及房地产投机现象,多次运用加息、提高存款准备金率等货币政策工具对宏观经济进行调控。本文运用货币政策有效性理论,并结合相关理论模型和统计数据,对1991~2010年期间的货币政策效果进行了实证分析。通过对理论模型与实际货币需求和货币供给变动的拟合程度进行检验,从货币供需变动角度分析了我国货币政策的有效性。     

矿用阻燃、抗静电聚丙烯防护网配方的研制

着重介绍矿用聚丙烯防护网的研制过程。通过添加溴系阻燃剂和抗静电剂对聚丙烯进行共混改性。实验结果表明 ,八溴联苯醚与 Sb2 O3 互配体系的氧指数可达 2 7以上 ;非离子型抗静电剂配以辅助抗静电剂 ,可使材料的表面电阻降至 3× 1 0 8Ω 以下     

Radial and non-radial decompositions of Luenberger productivity indicator with an illustrative application

Viewing slacks as one possible source of inefficiency, and that inputs have differential importance in the production process, this paper develops, based on the directional Russell measure of inefficiency, the non-radial Luenberger indicator. This indicator is then shown as the sum of the individual input-specific Luenberger indicators. The Luenberger indicator and its various input-specific indicators are also then shown as the composite measure of efficiency change and technical change. This decomposition enables the researcher to empirically examine the contributions of each factor input towards the productivity change and its components—efficiency change and technical change. Our proposed decomposition scheme is then empirically illustrated to analyze the eco-productivity performance behavior of the 22 OECD countries during the period 1995-2004. Our results indicate that first, the productivity change estimates yielded from the non-radial Luenberger indicator are different from those yielded from its radial counterpart, when slacks are present; second, most of these countries are found experiencing productivity growth due to technical progress alone; and finally, as regards the order of input-specific contributions towards productivity growth, capital contributes the most, followed by savings in emissions and labor, respectively.