Monte carlo evidence on the robustness of conditional moment tests in tobit and probit models

This paper numerically examines the size robustness of various conditional moment tests in misspecified tobit and probit models. The misspecifications considered include the incorrect exclusion of regressors, ignored heteroskedasticity and false distributional assumptions. An important feature of the experimental design is that it is based on an existing empirical study and is more realistic than many simulation studies. The tests are seen to have mixed performance depending on both the original null hypothesis being tested and type of misspecification encountered.     

Modeling Imbalanced Economic Recovery Following a Natural Disaster Using Input‐Output Analysis

Input‐output analysis is frequently used in studies of large‐scale weather‐related (e.g., Hurricanes and flooding) disruption of a regional economy. The economy after a sudden catastrophe shows a multitude of imbalances with respect to demand and production and may take months or years to recover. However, there is no consensus about how the economy recovers. This article presents a theoretical route map for imbalanced economic recovery called dynamic inequalities. Subsequently, it is applied to a hypothetical postdisaster economic scenario of flooding in London around the year 2020 to assess the influence of future shocks to a regional economy and suggest adaptation measures. Economic projections are produced by a macro econometric model and used as baseline conditions. The results suggest that London's economy would recover over approximately 70 months by applying a proportional rationing scheme under the assumption of initial 50% labor loss (with full recovery in six months), 40% initial loss to service sectors, and 10–30% initial loss to other sectors. The results also suggest that imbalance will be the norm during the postdisaster period of economic recovery even though balance may occur temporarily. Model sensitivity analysis suggests that a proportional rationing scheme may be an effective strategy to apply during postdisaster economic reconstruction, and that policies in transportation recovery and in health care are essential for effective postdisaster economic recovery.     

1-苯基环己硅烷类液晶化合物的量子化学研究──联苯基乙烷系列

运用ＰＭ３ 和ＡＭ１ 两种ＳＣＦ－ ＭＯ 方法，通过能量梯度全优化计算，给出了５ 种１－ 苯基环己硅烷类液晶化合物的稳定几何构型、电子结构和生成热、偶极矩等基本性质，并联系有机电子结构理论进行了讨论     

末态粒子相空间二维自仿射分形

在二维相空间对高能强子 -强子碰撞末态粒子的阶乘矩进行了研究 ,验证了高能粒子碰撞末态粒子相空间二维自仿射分形的性质 ,测定了其分形指数     

青年知识分子思想政治倾向的基本特征

青年知识分子思想政治倾向的基本特征主要表现在六个方面:一是青年知识分子作为思想活跃的一个社会群体,其思想政治倾向具有明显的时代性特征；二是青年知识分子随着年龄的不断增长、知识积累的不断完备及社会实践经验的不断丰富,其思想政治倾向也逐渐从不成熟到成熟、从不稳定到逐渐稳定,表现出鲜明的阶段性；三是成长、成熟于日益开放时代的青年知识分子,深受开放潮流的浸润,从而使其思想政治倾向具有明显的开放性特征；四是由于青年知识分子思想政治倾向形成时在主观上受着个人经历、认识水平和智能结构的限制,客观上又受历史时代、职业状况、经济状况、社会环境以及年龄等制约,因而必然表现出多样性特征；五是由于青年知识分子在生理上正处于青年时期,他们经常在日常生活中呈现出兴奋与苦闷、激动与烦恼、紧张与松懈等相互矛盾的心理状态,其思想政治倾向也由于个人人生得失、社会发展变革、重大社会事件和重要人物言行的影响而经常发生变动,因而具有鲜明的变动性特征；六是处于不稳定、不平衡状态之中的青年知识分子的思想政治倾向,可能向积极方向发展,也可能向消极方向发展。但是,思想政治倾向发展变化的方向是可以干预和引导的,即青年知识分子的思想政治倾向具有可塑性。     

指数基金投资策略研究

长期来看,绝大部分基金都不能跑赢指数基金,因此,普通投资者的最佳选择是投资指数基金.但投资指数基金应避免两个误区:一是在局部地区的长期熊市中不适合长期投资指数基金,二是在全球股市的长期熊市中不适合长期投资指数基金.而指数基金投资波段操作策略可有效避免以上两个投资误区,即每年5月至10月空仓、11月至次年4月投资指数基金.     

Staples,links, and poles in the construction of regional development theories

The developmental trajectories of extractive economies differ systematically from those of industrial economies. Analysis of these differences is difficult, because the specific characteristics and location in space of particular extracted resources distinguish extractive economies from each other far more than commodities produced and location distinguish industrial economies. The peculiar distoritions of Harold Innis's studies of particular staples as these were incorporated into general statements about regional economic development illustrate some of the tensions between ideographic and nomothetic goals in the analysis of regional economies and the dangers of resolving these tensions by collapsing the particular into the general. Subsequent use of these regional economic development models to obscure problems of particular resource extractive projects illuminates some of the unintended practical consequences of theoretical errors.     

关于单形体积与棱长的两个几何不等式

获得了涉及ｎ维单形的体积与棱长的两个几何不等式，推广了已有文献的有关结果．     

An alternative estimator for multiple characteristics in PPS sampling

The problem considered relates to large-scale sample surveys. A new estimator of population total for the characteristics that are poorly correlated with the selection probabilities has been developed for the PPSWR sampling scheme. The relative efficiency of the proposed estimator has been studied under a super-population model. A numerical investigation into the performance of the estimator has also been made.     

Exact inference for a simple step-stress model with competing risks for failure from exponential distribution under Type-II censoring

In reliability analysis, accelerated life-testing allows for gradual increment of stress levels on test units during an experiment. In a special class of accelerated life tests known as step-stress tests, the stress levels increase discretely at pre-fixed time points, and this allows the experimenter to obtain information on the parameters of the lifetime distributions more quickly than under normal operating conditions. Moreover, when a test unit fails, there are often more than one fatal cause for the failure, such as mechanical or electrical. In this article, we consider the simple step-stress model under Type-II censoring when the lifetime distributions of the different risk factors are independently exponentially distributed. Under this setup, we derive the maximum likelihood estimators (MLEs) of the unknown mean parameters of the different causes under the assumption of a cumulative exposure model. The exact distributions of the MLEs of the parameters are then derived through the use of conditional moment generating functions. Using these exact distributions as well as the asymptotic distributions and the parametric bootstrap method, we discuss the construction of confidence intervals for the parameters and assess their performance through Monte Carlo simulations. Finally, we illustrate the methods of inference discussed here with an example.