Reconceptualizing the effects of lean on production costs with evidence from the F-22 program

A central tenet in the theory of lean production is that the implementation of lean practices will reduce waste and thereby decrease costs. However, not all lean implementations have produced such results. Apparently, this effect is moderated by several factors, potentially even to the point of reversal. It is important to increase our understanding of how this might occur. In this paper, we explore how novelty, complexity, instability, and buffering affect the relationship between lean implementation and production costs. An interest in these factors drew us to study the case of Lockheed Martin's production system for the F-22, an extremely complex and innovative product. To build theory, we synthesize our empirical data from the case with other existing theory, such as theories of learning and complexity. Through this analysis, we develop a revised framework that reconceptualizes the effect of lean on production costs and use it to develop 11 propositions to direct further research. Included among these are propositions about how the timing, scale, and extent of lean implementation can regulate the benefits of lean. Furthermore, when the objective of lean is construed as the provision of value, we propose that this value is an emergent property of a complex process, different from the mere sum of the values provided by its constituent tasks. Therefore, the elimination of tasks will not guarantee cost reduction, and lean may provide even greater value by incorporating some aspects of agile manufacturing. Overall, we develop a fuller range of the effects of lean practices on production costs and illuminate how operations managers might control key variables to draw greater benefits from lean implementation.     

我国最低工资标准增长态势与测算方法分析

我国《促进就业规划》提出"十二五"时期绝大多数地区最低工资标准达到当地城镇从业人员平均工资的40%以上。但是目前绝大多数省份的最低工资标准明显低于当地城镇从业人员平均工资的40%。为实现"十二五"规划目标,有必要采用比例法来制定最低工资标准,即按照从业人员平均工资的适当比例来确定最低工资标准。各地采用比例法制定当地最低工资标准,关键是准确统计当地城镇从业人员的平均工资,把最低工资标准控制在当地平均工资的40%～60%之间。     

金融市场现代化背景下金融发展影响文化产业的实证分析

运用中国1995-2012年的时间序列数据,实证检验金融发展对文化产业的影响。结果显示,金融发展对文化产业规模有显著的正向影响,城镇居民可支配收入对文化产业规模有显著的负向影响,农村居民家庭人均纯收入对文化产业规模有显著的正向的影响,城镇居民恩格尔系数对文化产业规模有显著的正向影响。     

The Effects of Inverted Yield Curves on Asset Returns

Between 1954 and 1991, U.S. stocks, long-term government bonds, and corporate bonds show negative risk premiums during periods preceded by inverted yield curves. Intermediate-term government bonds do not. Going from safer to riskier asset classes, the negative risk premiums increase in absolute value and statistical significance. The consumption CAPM offers a possible explanation for the negative risk premiums. A negative covariance between the growth rate of consumption and the premium on the risky assets will result in a negative risk premium. Empirical tests of the conditional covariance show that the consumption CAPM does not explain the phenomena.     

零售业态均衡与创新的要素分析——基于零售业态价格梯度模型的研究

文章提出了一个业态价格梯度模型,该模型将价格梯度与业态竞争分布相联系,通过引入"消费者偏好"概念,较好地刻画了零售业态中服务、价格、成本三者之间关系,在此基础上验证并发展了"技术边界线"理论,提出业态取得竞争优势的关键因素是技术进步、满足消费者偏好以及管理创新带来的成本下降,我国家电零售业态历史发展变化情况也在一定程度上验证了模型的有效性。模型为今后同类研究提供量化分析工具的同时,也为进一步完善业态进化理论提供了新的研究视角。     

资本深化、结构变迁及劳动收入份额变动

本文通过构建一个具有要素密集度差异的两部门模型,分析了部门间TPP增长率差异、物质资本积累、恩格尔效应、以及部门进入壁垒变化对产业结构和劳动收入份额的影响.在资本深化且劳动密集型产品为优先需求的前提下,恩格尔效应将会导致劳动收入份额下降,并且这种效应渐近地趋于零;其次,部门TFP增长率差异、物质资本积累、产业壁垒变化对...     

室内配制混凝土单轴试验全应力-应变曲线试验研究

本文采用TAW-2000微机控制岩石伺服三轴压力试验机,对室内配制普通混凝土圆柱体试件(高径比约2:1)进行单轴受压实验。测定了普通混凝土全应力-应变曲线。通过对试验的研究,循环加载条件下,确实形成了一个封闭的塑性滞回环,且峰后塑性滞回环随循环的次数的增加而变小变窄;加载应力和加载段变形模量呈一定的线性关系;峰后卸载点的应力和峰值应力差越大,峰后曲线的变化越明显,变得越平缓,重新加载曲线的趋近线斜率与初始变形曲线的趋近线斜率相差越大。     

我国地价结构的土地经济学分析

地价是土地市场的重要指标,地价结构能有效反应土地市场结构和状况。我国地价结构为商业地价住宅地价工业地价农业地价,这与传统的土地竞价曲线不一致。本文从产业布局、城市规划、政策导向等角度,运用土地经济学分析方法,重构了我国的土地竞价曲线模式,并对我国地价结构进行了合理解释。结合我国实际,在借鉴日本地价结构比例的基础上,本文提出了适合我国的地价结构比例的建议。     

浅议恩格尔定律对我国全面建设小康社会的启示

该文通过改革开放以来人民生活水平不断提高的切身体验,纵观世界各国"恩格尔系数"的差别,分析各国社会、经济的发展轨迹,提出在加快社会主义现代化建设的进程中,必须认真实施科教兴国战略和经济发展与人口、资源、环境相协调的建议。     

乙酰丙酮分光光度法工作曲线稳定性研究

对乙酰丙酮分光光度法测定纺织品中甲醛含量的工作曲线稳定性进行了研究。实验结果表明,乙酰丙酮分光光度法工作曲线有良好的稳定性,相近环境温度不同贮存时间下所作工作曲线斜率的相对标准偏差（RSD）≤2.04%。