人民币汇率失衡及贸易壁垒对我国出口行业影响异质性研究

贸易摩擦、新冠疫情使我国经济贸易面临严峻挑战,人民币汇率波动及贸易壁垒将常态化地影响我国出口贸易.在加快形成以国内大循环为主体、国内国际双循环相互促进的新发展格局背景下,文章基于HS分类原则,选取WTO等机构的贸易数据,通过构建BEER模型测算了人民币汇率失衡程度;通过建立固定效应面板模型研究了人民币汇率失衡及贸易壁垒双因素对我国出口行业影响的异质性.研究表明:人民币汇率失衡对我国出口贸易整体上具有显著负向影响,非关税壁垒对我国出口贸易整体上具有显著正向影响;关税和非关税构成的贸易壁垒与人民币汇率失衡双因素对我国出口贸易具有显著抑制作用,并对不同出口行业的影响存在异质性;人民币汇率失衡与非关税壁垒双因素对大多行业均具有显著负向影响,人民币汇率失衡与关税壁垒双因素对不同行业影响的正负效应及程度大小有异质性.因此,建议通过运行逆周期因子等完善人民币汇率自我修正机制;通过引导出口企业了解使用外汇衍生品等促进外汇衍生品市场运行机制的健全;通过加强"海外仓"建设及深耕RCEP框架下的东盟十国市场等实施出口行业差异化贸易策略;通过提升自主科技创新能力等加快出口行业产业转型升级,推动双循环,实现我国出口贸易高质量发展.     

储层岩石矿物成分对酸蚀裂缝导流能力的影响

储层岩石矿物成分是酸压改造效果影响因素之一。研究认为，在储层岩石矿物成分中易溶物的含量及分布方式决定了酸蚀裂缝导流能力大小，易溶蚀物的含量越多，岩石溶蚀速率越快。室内测试了不同溶蚀速率下的灰岩和白云岩的酸蚀裂缝导流能力，研究了岩石溶蚀速率、易溶蚀物含量对酸蚀裂缝导流能力的影响，对酸压工艺设计方案提出了指导性建议。研究结果表明，储层岩石溶蚀速率与酸蚀裂缝导流能力增加倍比存在抛物线关系，易溶蚀物占30%40% 时酸蚀裂缝导流能力保持较好。     

Frontier spaces of vulnerability: Regional change,urbanization, drought and fire hazard in Santarém,Pará, Brazil

Fire hazard is a mounting concern in tropical rainforests of the Brazilian Amazon and has raised awareness within the science community of the links between agricultural fire use, drought and accidental fire. As a result, fire is being addressed as a crisis event with mitigation focused on those who light fires, particularly smallholder agriculturalists. Little attention is paid to the historical and ongoing ways in which Amazon landscapes and peoples have been made more susceptible to fire. Frontier regions of the Brazilian Amazon serve a variety of functions within the larger Brazilian society, including as extractive reserves for economic development, as social safety valves to reduce population pressures, and as areas to support urban regional integration. Each of these functions has impacted frontier environments in ways that create more flammable landscapes and/or shape the vulnerability of people to fire hazard. This paper uses a case study inthe Brazilian Lower Amazon to understand how vulnerability to fire hazard develops. It argues that if fire mitigation remains centered on fire as a crisis event, an understanding of what constitutes frontier spaces of vulnerability, both in landscape and in populations, will be limited.     

Kernel Estimation of Rate Function for Recurrent Event Data

Abstract.  Recurrent event data are largely characterized by the rate function but smoothing techniques for estimating the rate function have never been rigorously developed or studied in statistical literature. This paper considers the moment and least squares methods for estimating the rate function from recurrent event data. With an independent censoring assumption on the recurrent event process, we study statistical properties of the proposed estimators and propose bootstrap procedures for the bandwidth selection and for the approximation of confidence intervals in the estimation of the occurrence rate function. It is identified that the moment method without resmoothing via a smaller bandwidth will produce a curve with nicks occurring at the censoring times, whereas there is no such problem with the least squares method. Furthermore, the asymptotic variance of the least squares estimator is shown to be smaller under regularity conditions. However, in the implementation of the bootstrap procedures, the moment method is computationally more efficient than the least squares method because the former approach uses condensed bootstrap data. The performance of the proposed procedures is studied through Monte Carlo simulations and an epidemiological example on intravenous drug users.     

Book Reviews

Books reviewed:
M Hollander and D Wolfe, Nonparametric Statistical Methods
T Leonard and J.S.J Hsu, Bayesian Methods     

论证券市场化解委托代理风险的作用机制

本文首先探讨了证券市场化解股份有限公司代理人道德风险问题的作用机制 ,并进一步详尽地分析了该机制发挥作用需要具备的条件 ,包括 :证券市场存在、证券市场具有完善的信息交流功能、证券市场有效性较高等。文章继而对照上述条件分析了我国证券市场的现状。最后提出了改进的对策     

大学排序行为模式不规范性及其负面影响

当代大学选优排序已成为社会参与高等教育管理、促进大学竞争与发展的重要途径。但是 ,目前社会流行的不规范的选优排序活动已经在高校和社会产生了误导和不良影响。对此进行了分析 ,并提出整顿与规范大学选优排序的几点意见。     

A Semi-parametric Regression Model with Errors in Variables

Abstract.  In this paper, we consider a partial linear regression model with measurement errors in possibly all the variables. We use a method of moments and deconvolution to construct a new class of parametric estimators together with a non-parametric kernel estimator. Strong convergence, optimal rate of weak convergence and asymptotic normality of the estimators are investigated.     

我国第三产业发展及劳动就业增长的实证分析

首先介绍了我国第三产业发展的现状 ,然后通过计算第三产业发展过程中的劳动就业贡献率和就业弹性 ,分析了我国第三产业发展吸纳劳动力的潜力。最后对第三产业发展及扩大就业提出几点建议。     

飞灰冲蚀条件下材料抗磨性能的试验研究

本文首先综述了国内外学者在研究塑性材料耐冲蚀磨损性能方面所取得的主要成果,并在专门建立的灰磨试验台上,对电站燃煤锅炉对流受热面常用材料20号钢、12Cr_1MoV合金铜以及铜、铝四种塑性材料进行了耐飞灰冲蚀磨损性能的试验研究。提出用材料的体积磨损率来定义材料的耐冲蚀磨损性能系数。并用它表征塑性材料的抗磨性能。该系数可直接应用于计算燃煤锅炉对流受热面的安全烟速。