Tactical production and distribution planning with dependency issues on the production process

Tactical production-distribution planning models have attracted a great deal of attention in the past decades. In these models, production and distribution decisions are considered simultaneously such that the combined plans are more advantageous than the plans resolved in a hierarchical planning process. We consider a two-stage production process, where in the first stage raw materials are transformed into continuous resources that feed the discrete production of end products in the second stage. Moreover, the setup times and costs of resources depend on the sequence in which they are processed in the first stage. The minimum scheduling unit is the product family which consists of products sharing common resources and manufacturing processes. Based on different mathematical modelling approaches to the production in the first stage, we develop a sequence-oriented formulation and a product-oriented formulation, and propose decomposition-based heuristics to solve this problem efficiently. By considering these dependencies arising in practical production processes, our model can be applied to various industrial cases, such as the beverage industry or the steel industry. Computation tests on instances from an industrial application are provided at the end of the paper.     

The efficiency of mutual fund companies: Evidence from an innovative network SBM approach

This paper is the first DEA (Data Envelopment Analysis) evaluation of the efficiency of a sample of mutual fund companies in a large Euro fund industry, i.e. Spain. Our novel network model links the efficiency of the core activities (portfolio management and marketing/distribution) of a mutual fund company to the efficiency of its operational management function. Our results highlight the important networking effects at the marketing stage and question the prime role of portfolio management skills in the overall efficiency of a mutual fund company. The evaluation of robust efficiency clusters indicates that the efficiency rankings obtained with our network model persist significantly along our sample period. Finally, the application of the SBM (Slacks-Based Measure) Variation III to our network model allows us to identify a large number of globally inefficient but locally efficient companies with reference to competitors with similar management resources.     

适应性市场假说及其在中国资本市场的实证

金融危机近些年爆发频繁,传统市场理论如有效市场假说和行为金融面对复杂的现实金融世界未能给出合理解释.Lo提出的适应性市场假说则弥合了这两个学派的分歧,逐渐引起了学术界的重视.本文尝试从动态市场效率、时变贝塔和技术交易策略演变这三个角度对适应性市场假说能否解释我国资本市场进行实证研究.研究发现:我国股票市场效率在动态变化,无效的时段与金融危机或政策巨变等重大事件联系密切;股市风格指数贝塔随市场环境变化而改变;技术交易策略绩效随投资者适应环境变化而演变.研究结果表明,适应性市场假说相比有效市场假说和经典资本资产定价模型,能够更好地解释我国资本市场上述现象.最后对投资者如何根据市场环境变化制定适应性投资策略给出几点建议.     

湖北省主要农产品技术效率与规模经济性的实证考察

采用超越对数生产函数形式的随机前沿模型,对湖北省2003年农产品生产的规模经济性和技术效率进行了分析比较,得出以下结论：（1）物质费用和播种面积是重要的生产投入要素,对产量的贡献基本上为正;（2）劳动投入的产出弹性有正有负;（3）各农产品的平均规模经济效果不明显,只有小麦的生产规模经济递增;（4）各种农产品的技术效率水平存在较大差距,其中棉花、蔬菜、禽肉最高,而水果、生猪最低。最后,得出两点政策建议：一是应克服技术创新的障碍因素,调动科研、推广和生产三方面的积极性,使农业科技在今后的农业增长中得到最大的发挥;二是建立新型的经营组织,以解决农业基础技术设施的投资问题。     

跨国公司经营业绩评价方法的研究

跨国公司经营业绩评价较之国内经营企业的经营业绩评价有其特殊的复杂性。本文提出跨国公司经营业绩评价的一种新方法,构造跨国公司经营业绩评价标准的综合效用值模型,建立跨国公司经营业绩评价系统的整体模型。     

不确定性、学习与新技术序列投资决策

以不同性质不确定性与其解决方式(学习)和效率对投资价值的影响为切入点,研究新技术序列投资行为背后的决策机制与路径.在现有研究基础上,引入企业内部学习的异质性特征,把技术不确定性的解决效率分解为学习能力、累积学习效应与边际学习效应3个层次进行讨论.运用实物期权方法构建包含学习效应的新技术序列投资决策模型,并得到最优决策规则,通过数值方法对不同参数进行比较静态分析,并阐述结果的经济与管理涵义.     

基于投入产出技术的能源效率新指标——生产能耗综合指数

随着全世界对能源需求的增加,以及全球气候变化之于人类的负面影响逐渐加剧,能源效率的高低已成为衡量一国经济、政治和环境发展的重要标志。但是现有的能源效率指标在国内国际比较中并不能更好的发挥作用,鉴于此,本文在投入产出技术框架下,提出生产能耗综合指数这一比较能源效率的新指标,以此能更加完善我国能源效率的评价体系,更加科学合理的指导经济建设,指明节能工作的主要方向。     

我国全要素能源效率的测度与分析

考虑到能源与资本、劳动力等投入要素间普遍存在的替代效应,本文通过全要素能源效率指标考察我国能源利用水平的时空变化特征,并利用计量模型分析全要素生产率各分解部分对能源效率的影响作用。研究表明:我国总体及区域内的全要素能源效率自2001年起出现了退化现象,区域间能源效率的差异性较为显著,且有扩大趋势;全要素能源效率与全要素生产率之间关系密切,技术进步、纯技术效率和规模效率对能源效率的改善均具有促进作用,软技术的贡献甚至已超越了传统科技进步的功效。     

Slack free MEA and RDM with comprehensive efficiency measures

This paper extends two directional distance function models, the Multi-directional Efficiency Analysis (MEA) Model and the Range Directional Model (RDM), in order to account for any type of technical inefficiency, i.e. both directional and non-directional inefficiencies. We first focus on the variable returns to scale (VRS) case, because both VRS-MEA and RDM are translation invariant models, which mean that both models are able to deal with negative data. Our main result is the definition of a new comprehensive efficiency measure which is units invariant and translation invariant and covers both models. Secondly, we introduce the RDM model under constant returns to scale (CRS) together with a new comprehensive efficiency measure.