Boundedly complete families which are not complete

Summary Completeness of a family of probability distributions implies its bounded completeness but not conversely. An example of a family which is boundedly complete but not complete was presented by Lehmann and Scheffe [5]. This appears to be the only such example quoted in the statistical literature. The purpose of this note is to provide further examples of this type. It is shown that any given family of power series distributions can be used to construct a class containing infinitely many boundedly complete, but not complete, families. Furthermore, it is shown that the family of continuous distributions , is boundedly complete, but not complete, whereU denotes the uniform distribution on [a, b] and {P _ϑ,ϑ ∈ IR}, is a translation family generated by a distributionP ₀ with mean value zero, which is continuous with respect to the Lebesgue measure.     

行为金融述评：渊源、定位与在中国的研究

由于标准金融学的理性人假设和有效市场假说的缺陷,行为金融以心理学和行为学为基础,提出有限理性和非有效市场,来解释金融市场的异象,这是对标准金融学的强有力挑战。标准金融学和行为金融学之间的差异是研究目标不同。标准金融学描述经济个体的最优决策行为,而行为金融描述的是真实决策行为。文章综合了国内外的研究文献,对行为金融的渊源和定位作出综述,并提出目前行为金融的研究框架内容和在中国的研究展望。     

Linear learning in changing environments

The decision maker receives signals imperfectly correlated with an unobservable state variable and must take actions whose payoffs depend on the state. The state randomly changes over time. In this environment, we examine the performance of simple linear updating rules relative to Bayesian learning. We show that a range of parameters exists for which linear learning results in exactly the same decisions as Bayesian learning, although not in the same beliefs. Outside this parameter range, we use simulations to demonstrate that the consumption level attainable under the optimal linear rule is virtually indistinguishable from the one attainable under Bayes’ rule, although the respective decisions will not always be identical. These results suggest that simple rules of thumb can have an advantage over Bayesian updating when more complex calculations are more costly to perform than less complex ones. We demonstrate the implications of such an advantage in an evolutionary model where agents “learn to learn.”     

完全信息动态条件下企业总成本领先战略探究

首先,从迈克尔.波特教授的著作中引入总成本领先战略;接着,从博弈论斯坦克尔伯格模型出发,来建立所要分析问题的一般化模型,并分析一般化的完全信息动态模型得到均衡解。在结论分析中,引入要讨论的总成本领先战略,通过对比分析先动的企业和跟随的企业在采取成本领先的时候其市场的份额和利润,得到讨论的结论;先动的企业采取成本领先可以获得行业竞争优势,跟随企业在采取足够低的成本领先的前提下,也可以获得更高的市场份额和利润空间,从而可以获得竞争优势。     

生态产品供给的内生动力机制释析 ——基于完整价值回报与代际价值回报的双重视角

研究目的：从生态产品完整价值回报和代际价值回报两个视角,应用资源价值构成理论和外部性理论,探究生态产品供给内生动力不足的原因以及提升内生动力的策略。研究方法：成本效益分析方法和情景模拟方法。研究结果：生态产品供给的内生动力缺失的原因在于供给主体缺乏合理的完整价值回报和代际价值回报：一方面,由于生态价值评价体系的缺失和地方政府的职责推诿抑制了生态价值的实现,部分地区人力资本和人造资本的短板约束了社会文化价值的实现;另一方面,缺失适用于生态产品供给的社会折现率体系和相关的代际补偿机制导致了生态产品供给在当前收益与未来收益间存在转换偏差,降低了供给行动的代际回报。研究结论：提升生态产品供给的内生动力可从两方面着手：一方面需要建立不同类型的价值评价体系,拓宽生态价值实现渠道,明晰政府在价值实现中的职责;另一方面需要建立符合生态产品特点的新代际折现率体系,参照新代际折现率和传统折现率核算得到的净现值差额制定代际补偿标准,探索考虑代际影响的代际金融产品,根据价值替代难度建立健全生态产品价值实现机制。     

工程量清单招标方法的探讨

工程量清单招标是国际上普遍使用的通行做法。它适应市场并合理配置资源,有利于施工企业合理报价,实现优胜劣汰,有利于标底的管理和控制,合理分散风险等,是我国工程造价体制改革的必然走向。     

精准扶贫过程中工具理性的越位和价值理性的回归——基于湖北省B村的调查

精准扶贫包含着以效率为核心的工具理性和以人文价值为核心的价值理性,以两种理性视角审视湖北省B村的扶贫现状,发现B村精准扶贫在实施过程中出现工具理性和价值理性的失衡,主要表现为政策形式偏离价值初衷、效率优先忽视公平诉求、技术思维淡化人文关怀等问题,工具理性僭越到价值理性之上。为了促进扶贫工作顺利开展和扶贫任务的圆满实现,必须要推进精准扶贫过程中科学与民主、效率与公平、扶贫与扶志、扶智的统一,来助力价值理性的回归。     

Three decades of productivity change in French beef production: a Färe‐Primont index decomposition

The Färe‐Primont index is used to evaluate total factor productivity (TFP) change and its components for a sample of French suckler cow farms in grassland areas in 1985–2014. The results reveal an increase in TFP of 6.6 per cent over the whole observation period, with technological progress being the major source of productivity growth. Meanwhile, efficiency decreased. Farms experienced great technological progress from 1991 to 2000. From a methodological point of view, the comparison with results obtained with Malmquist indexes shows similar trends but different magnitudes, with the Malmquist index overestimating the TFP and technological changes compared to the Färe‐Primont index. In addition, the use of a sequential approach that restricts technological change to being positive or null allows for the precise calculation of technology changes, disregarding the effects of external conditions that are captured in efficiency changes. Finally, the estimation of full dimensional efficient facets (FDEFs) that guarantees the positivity of all shadow prices used to assess the mix efficiency component of TFP change is promising.     

从经济理性到有限理性:经济学研究理性假设的演变

"经济理性"是经济学的传统研究假设,却因背离现实而受到质疑.基于行为人稀缺的心理资源和系统固有的不确定性而产生的"有限理性"正逐步取代"经济理性"成为经济学研究的理性假设.不同的理性观点可以从决策的视角得到系统地解释和比较.并且,随着理性假设的演变,经济行为的决策标准也相应从单一静态最优向多元动态平衡转变.     

用加重方法完全平衡平面机构惯性力的条件

在平面杆机构的设计中 ,惯性力的平衡是经常遇到的问题。本文经推导给出了用加重法完全平衡平面杆机构惯性力的条件