中国城镇化:历史道路、制度根源与国际经验

中国城镇化发展的每一个历史阶段,都对应了中国经济社会发展中需要解决的核心问题。当前中国城镇化发展面临的瓶颈,其形成有深刻的社会历史制度根源。要从全球及中国发展大战略的角度,历史性地考察中国城镇化道路的历史演变及其逻辑,探寻中国城镇化发展瓶颈的社会历史制度根源,并借鉴国际经验,推动新型城镇化的健康发展。为此,需要在战略认知方面,突破城镇化发展传统思维的束缚,形成创新性的新型城镇化发展战略的理念;在制度建构方面,形成推动和保障城镇化发展的有针对性的战略框架;在动员多元主体力量与资源方面,要实行多元主体间的协调合作,打造城镇化发展的组织化支持系统。     

长江流域的消费函数:基于非稳定面板数据的分析

运用面板单位根与面板协整方法研究长江流域的消费函数。基于10省(市)1981-2003年的宏观消费与收入的面板数据,研究发现消费与收入存在显著的面板协整关系,边际消费倾向也非常稳定,稳定在0.7-0.85之间。为此,应采取鼓励消费的政策,从而促进经济长期增长。     

On the Bootstrap of the Maximum Score Estimator

This paper shows that the bootstrap does not consistently estimate the asymptotic distribution of the maximum score estimator. The theory developed also applies to other estimators within a cube‐root convergence class. For some single‐parameter estimators in this class, the results suggest a simple method for inference based upon the bootstrap.     

沪市认购权证与其标的股票价格走势的Granger因果检验

运用G ranger因果检验的方法,检验沪市6只认购权证与其标的股票之间的因果关系。分析结果表明:在大样本条件下,认购权证与其标的股票之间存在单向的G ranger因果关系,权证的价格走势影响其标的股票的价格走势,说明从长期来看,认购权证发挥了其潜在的投资杠杆的作用,其价值发现与风险对冲功能在市场中得到实现;在小样本条件下,认购权证与其标的股票之间不存在显著的G ranger因果关系,表明短期内权证与其标的股票价格走势相互独立,市场中有可能存在对权证投机炒作,人为放大权证的投资风险,使权证背离其正常的投资价值。     

Leveraging risk assessment for foodborne outbreak investigations: The Quantitative Risk Assessment-Epidemic Curve Prediction Model

Root cause analysis can be used in foodborne illness outbreak investigations to determine the underlying causes of an outbreak and to help identify actions that could be taken to prevent future outbreaks. We developed a new tool, the Quantitative Risk Assessment-Epidemic Curve Prediction Model (QRA-EC), to assist with these goals and applied it to a case study to investigate and illustrate the utility of leveraging quantitative risk assessment to provide unique insights for foodborne illness outbreak root cause analysis. We used a 2019 Salmonella outbreak linked to melons as a case study to demonstrate the utility of this model (Centers for Disease Control and Prevention [CDC], 2019). The model was used to evaluate the impact of various root cause hypotheses (representing different contamination sources and food safety system failures in the melon supply chain) on the predicted number and timeline of illnesses. The predicted number of illnesses varied by contamination source and was strongly impacted by the prevalence and level of Salmonella contamination on the surface/inside of whole melons and inside contamination niches on equipment surfaces. The timeline of illnesses was most strongly impacted by equipment sanitation efficacy for contamination niches. Evaluations of a wide range of scenarios representing various potential root causes enabled us to identify which hypotheses, were likely to result in an outbreak of similar size and illness timeline to the 2019 Salmonella melon outbreak. The QRA-EC framework can be adapted to accommodate any food–pathogen pairs to provide insights for foodborne outbreak investigations.     

Modern likelihood inference for the maximum/minimum of a bivariate normal vector

ABSTRACT

We consider the use of modern likelihood asymptotics in the construction of confidence intervals for the parameter which determines the skewness of the distribution of the maximum/minimum of an exchangeable bivariate normal random vector. Simulation studies were conducted to investigate the accuracy of the proposed methods and to compare them to available alternatives. Accuracy is evaluated in terms of both coverage probability and expected length of the interval. We furthermore illustrate the suitability of our proposals by means of two data sets, consisting of, respectively, measurements taken on the brains of 10 mono-zygotic twins and measurements of mineral content of bones in the dominant and non-dominant arms for 25 elderly women.     

New innovational outlier unit root test with a break at an unknown time

The Perron test which is based on a Dickey–Fuller test regression is a commonly employed approach to test for a unit root in the presence of a structural break of unknown timing. In the case of an innovational outlier (IO), the Perron test tends to exhibit spurious rejections in finite samples when the break occurs under the null hypothesis. In the present paper, a new Perron-type IO unit root test is developed. It is shown in Monte Carlo experiments that the new test does not over-reject the null hypothesis. Even for the case of a level and slope break for trending data, the empirical size is near its nominal level. The test distribution equals the case of a known break date. Furthermore, the test is able to identify the true break date very accurately even for small breaks. As an application serves the Nelson–Plosser data set.     

Structural changes and unit roots in non-stationary time series

The problem of testing hypotheses of a unit root and a structural change in one-dimensional time series is considered. A non-parametric two-step method for solution of the problem is proposed. The method is based upon the modified Kolmogorov-Smirnov statistic. At the first step of this method the hypothesis of stationarity of an obtained sample is tested against a unified alternative of a statistical non-stationarity of a time series (a unit root or a structural change). At the second step of the proposed method, in case of rejecting the stationarity hypothesis at the first step, the hypothesis of an unknown structural change is tested against the alternative of a unit root. We prove that probabilities of errors (false classification of hypotheses) of the proposed method converge to zero as the sample size tends to infinity.     

农村基础设施及其空间溢出效应对农村经济增长的影响

现有经验研究的文献对农村基础设施与农村经济增长的关系具有2种相反的结论,其主要原因在于忽略了农村基础设施的存在空间溢出效应。利用1997-2008年我国省级农村经济增长数据和完全修正普通最小二乘法的面板协整估计,研究了农村基础设施及其空间溢出效应对农村经济增长的影响。结果显示：农村基础设施资本存量对我国农村经济增长具有显著的促进作用,而且农村基础设施资本存量也具有显著的空间溢出效应。这表明政府在加大对农村基础设施的投入力度的同时,还应协调相邻地区的农村基础设施投资,以充分发挥农村基础设施的最大经济效益,推动当地及相邻地区的农村经济增长。     

企业党建工作必须体现先进性建设这个根本

先进性建设是企业党建工作的根本.要增强党的先进性必须仅仅围绕发展经济这个中心任务来进行;必须实现好,维护好,发展好广大职工群众的根本利益;必须不断增强企业党组织的执政能力建设;必须在继承和创新中构建保持党的先进性的长效机制.