A note on the difference between two likelihood based methods in growth curves

A new result is proved on the difference between ML and REML in the classical growth curve model, concerning the estimated variances of the regression coefficients. Simulations indicate that REML provides estimated variances closer to their true corresponding values, giving confidence intervals which are not misleadingly short.     

选择与限制:生育过程中的终止妊娠措施——基于规范和实践层面的价值权衡

终止妊娠问题在规范层面一是作为对于违反计划生育规定生育子女的行为所采取的纠正措施之一而存在的;二是对基于非医学需要性别鉴定/选择的终止妊娠的禁止,但存在当事人终止妊娠的动机难以确定、控制性别比例的初衷难以实现、对符合生育条件的妇女与不符合生育条件的妇女区别对待、缺乏设定行政许可的上位法依据等问题。在实践层面上,选择性别的终止妊娠未得到真正禁止。规范与实践层面问题背后的出路在于厘清问题所涉及到的权利冲突,并对其进行价值权衡。     

关于促进农民增收的财政政策的思考

目前农民收入增长趋缓已引起党和政府的高度重视.本文从农民收入现状入手,从财政政策角度分析了农民收入增长趋缓的原因,提出了促进农民增收的财政对策.     

基于结构突变的兵团和新疆经济增长的协整分析

该文采用结构突变与协整分析,研究新疆生产建设兵团和新疆1952-2006年GDP增长的相关关系。结果显示,兵团GDP序列及兵团和新疆经济的协整关系在1975年前后发生了突变,以此为依据分别从整体和两个区间1952-1973年和1978-2006年论证了兵团和新疆的GDP增长均存在显著的协整关系。但是通过格兰杰因果关系检验发现在整个样本区间及1978-2006年区间内,兵团的GDP增长均不显著影响新疆经济,但是在1952-1973年内兵团和新疆的经济增长有双向的促进作用。     

Growth and trade in the United States and the world economy: Overview

After the slow recovery from the 2008–2009 global financial crisis, the world economy faced slower growth than in the previous decade and even the prospect of a new global financial crisis. This paper starts by examining the reasons for the slow economic recovery and growth in the after the 2008–2009 global financial crisis and "great recession". Then, it examines the reasons the United States grew faster than other advanced countries (especially Europe and Japan), the slowing growth of emerging market economies (and even economic crisis in some of them), and whether the world is now (February 2020) sliding toward a new global financial crisis and recession.     

A sign of the times? Weak and strong polarization in the U.S. Congress, 1973–2016

Claims that the United States Congress is (becoming more) polarized are widespread, but what is polarization? In this paper, I draw on notions of intergroup relations to distinguish two forms. Weak polarization occurs when relations between the polarized groups are merely absent, while strong polarization occurs when the relations between the polarized groups are negative. I apply the Stochastic Degree Sequence Model to data on bill co-sponsorship in both the U.S. House of Representatives and U.S. Senate, from 1973 (93rd session) to 2016 (114th session) to infer a series of signed networks of political relationships among legislators, which I then use to answer two research questions. First, can the widely reported finding of increasing weak polarization in the U.S. Congress be replicated when using a statistical model to make inferences about when positive political relations exist? Second, is the (increasing) polarization observed in the U.S. Congress only weak polarization, or is it strong polarization? I find that both chambers exhibit both weak and strong polarization, that both forms are increasing, and that they are structured by political party affiliation. However, I also find these trends are unrelated to which party holds the majority in a chamber.     

国际收支危机模型的演化逻辑及其现实困境——基于全球金融危机视角的分析范式

本文系统地回顾了国际收支危机模型的理论背景、假设前提及其基本原理，同时，将西方其他学者就国际收支危机模型的进一步拓展进行了系统的分析和解释，并从全球金融危机视角考察了理论解释危机现象的突出优势和面临的现实困境。     

能源化工产业高级化与经济增长——兼论能源化工产业最优匹配

能源化工产业是重要的基础性产业，现阶段对能源化工产业高级化及其对经济增长影响研究的成果还较少。文章首先将能源化工产业分为能源开采业、能源加工业和化工产业三大产业，测算能源化工产业高级化水平，结果表明能源资源禀赋导致了能源化工高级化水平的“低端锁定”，能源富集区能源产业高级化水平远远低于非能源富集省份，能源化工产业空间错配现象突出。其次，实证检验能源化工产业高级化对经济增长的影响，结果表明提高能源化工高级化水平能够显著促进经济增长，且不同产业规模的能源化工产业高级化对经济增长的影响存在差异性。再次，采用滚动回归方法检验随着能源化工产业高级化水平和产业结构变动，能源化工产业高级化水平对经济增长影响的变动状况，探讨能源化工产业内部最优匹配问题，结果表明能源化工产业高级化水平在1.05-1.15之间、能源开采业占能源化工产业比重在0.20-0.40之间，能源化工产业高级化对经济增长的促进效应最大。最后提出优化能源富集区能源化工产业匹配度、促进化工产业富集区新产品和新技术研发以及缓解能源化工产业空间错配等方面的政策建议。     

我国创业板市场与中小板市场动态相关性实证研究——基于方法比较视角

DCC—GARCH模型能较好地刻画金融市场间的线性动态相关性,而时变相关的正态Copula模型主要用于考察金融市场间的非线性动态相关性,选取创业板指数（399006）和中小板指数（399005）,通过对两大指数收益率序列进行建模,基于DCC—GARCH模型和Copula模型分别计算两市场间的动态相关系数,以考察两市场间的动态相关性。研究结果表明：①创业板市场与中小板市场存在正相关关系,且相关性很强;②时变Copula模型因捕捉了市场收益率随时间变化的特性,在刻画金融市场问的相关性方面,效果要优于常相关Copula模型;③除个别时点外,DCC—GARCH模型计算的动态相关系数处于稳定的区间,而Copula模型计算的动态相关系数会表现出异常值的出现,这是由于其考虑了市场间的非线性因素所致,效果优于前者。