Estimation of the scale matrix of a multivariate t-model under entropy loss

This paper deals with the estimation of the scale matrix of a multivariatet-model with unknown location vector and scale matrix to improve upon the usual estimators based on the sample sum of product matrix. The well-known results of the estimation of the scale matrix of the multivariate normal model under the assumption of entropy loss function have been generalized to that of a multivariatet-model. The paper is based on the first author’s unpublished Ph.D. dissertation ‘Estimation of the Scale Matrix of a Multivariate T-model’, University of Western Ontario, Canada. Present address: School of Mathematics and Statistics, The University of Sydney, NSW 2006, Australia.     

On estimating the reliability after sequentially estimating the mean: The exponential case

Sequential estimation problems for the mean parameter of an exponential distribution has received much attention over the years. Purely sequential and accelerated sequential estimators and their asymptotic second-order characteristics have been laid out in the existing literature, both for minimum risk point as well as bounded length confidence interval estimation of the mean parameter. Having obtained a data set from such sequentially designed experiments, the paper investigates estimation problems for the associatedreliability function. Second-order approximations are provided for the bias and mean squared error of the proposed estimator of the reliability function, first under a general setup. An ad hoc bias-corrected version is also introduced. Then, the proposed estimator is investigated further under some specific sequential sampling strategies, already available in the literature. In the end, simulation results are presented for comparing the proposed estimators of the reliability function for moderate sample sizes and various sequential sampling strategies.     

空中庭院与半围合式住宅感知密度的关联性研究——以广州万科峯境为例

在半围合式城市住宅中,感知密度是居住体验的重要环节。空中庭院能够缓解高密度环境中的拥挤感,优化其空间形态,是改善环境感知的建构基础。使用虚拟现实技术进行密度感知实验,能探讨与空中庭院形态相关的视觉因素——可视性和绿视率对环境感知密度的影响。将广州万科峯境作为原型建立15组以可视性与绿视率为变量的实验模型,通过采集受试者对不同环境感知密度的主观评价,反映实验样本的空间特征,进而分析主观评价与客观量化之间的关联机制。分析结果表明：半围合式城市住宅空中庭院的可视性与绿视率是影响居住环境感知密度的重要因素;呈线状分布的、具有视觉层次性的空中庭院更受大众青睐。     

Nonlinearities in the real exchange rates: new evidence from developed and developing countries

This paper investigates nonlinearities in the dynamics of real exchange rates. We use Monte Carlo simulations to establish the size properties of the Teräsvirta-Anderson test, when the dynamics of the real exchange rate is influenced by an exogenous process. In addition, we show that a modified nonlinearity test, which includes additional right-hand-side variables, performs much better than the original in both Monte Carlo exercises and in the actual data on 1431 bilateral real exchange rate series. Finally, we investigate the dynamics of the real exchange rate for both developed and developing countries using the modified test for the recent floating period. In general, the results find a greater incidence of nonlinear dynamics for developing country real exchange rates.     

Nonlinearity in dynamic adjustment: Semiparametric estimation of panel labor supply

We estimate a semiparametric dynamic panel data model by the local linear kernel method and we interpret the slope of the nonparametric component function as a varying slope coefficient. Thus, the slope coefficient is a smooth, but otherwise unknown, function of some of the regressors. A Monte Carlo experiment is reported to examine the finite sample performance of the local linear estimator. We apply the estimation method to a labor supply equation for men from the triannual Survey of Income and Program Participation (SIPP). Specification tests based on the estimated labor supply elasticities, partial adjustment coefficients, and residuals demonstrate the improvements from a semiparametric partially linear model. Our empirical results point to a need by economists to revisit the issue of the speed of labor market adjustment to policy induced shifts in labor demand and to take more formal econometric account of heterogeneity in wage effects when studying the distributional consequences of tax reforms for labor supply earnings. First version received: July 2000/Final version received: January 2001     

环境质量变化对游客福利的影响——基于旅行费用和条件行为联合数据

环境质量是影响游客旅游需求及福利的重要因素,但单一使用陈述性偏好法或揭示性偏好法仍存在诸多局限性。为探究环境质量改变对游客需求及福利变化的具体影响,结合旅行费用与条件行为数据,在明确现有环境质量状况下景区价值基础上,评估环境质量改善与恶化两种情景下,游客消费者剩余的变化。结果表明,环境质量改变直接影响旅行次数,从而增加或减少消费者剩余,但不会通过影响游客旅行费用间接改变消费者剩余,实际行为与条件行为数据偏好存在一致性;白洋淀景区当前消费者剩余为909.09元/次;环境质量改善使游客平均旅行次数增加1.45次/年,并使每位游客每年的消费者剩余增加1 318.18元;环境质量恶化使游客平均旅行次数降低1.41次/年,并使每位游客每年的消费者剩余减少1 281.81元。     

Recovering Hicksian Consumer Surplus within a Collective Model: Hausman's Method for the Household

The purpose of this paper is to describe the implications of the collective model of household behavior for the methods used to estimate the economic value of non-marketed environmental resources. After demonstrating how the separability restrictions inherent in the collective model allow individual preference and household income allocation choices to be distinguished, the paper demonstrates how the framework can be used to recover Hicksian consumer surplus. An algebraic example is used to illustrate how the framework can be used in valuing environmental resources.     

基于生态-技术创新和熵理论的企业绿色创新风险度量研究

历史的考察表明,企业进程的实然状态是非生态化的,而生态觉醒之后的企业发展的应然趋势是生态化,导致二者背离的恰恰是作为推动企业发展的＂技术创新→利润＂中轴。随着绿色消费在全球的兴起,绿色企业将成为未来的新型主导企业。文章基于可持续发展的视角,将生态理论和熵理论引入技术创新风险管理领域,建立了基于生态-技术创新和熵理论的技术创新风险度量模型,并将该模型用于企业对技术创新项目进行风险度量和决策。     

中国城乡有效经济增长的差异性分析

本文提出了有效经济增长的概念,构建了有效经济增长动态模型,利用该模型建立了超额人均收入等相关变量的测定方法。在此基础上分别测算我国城镇部门与农村部门有效经济增长的相关指标,并进行比较分析。结果发现,改革开放以来我国城镇部门有效经济增长无论从绝对量上还是增长速度上都明显高于、快于农村部门;城镇部门有效经济增长的减损量大于农村部门;而农村部门对有效经济增长的减损强度却大于城镇部门。因此,推动城市化且合理控制城市化进程的速度,是降低我国有效经济增长的减损强度,实现有效经济增长可持续性的有力途径。