Learning equilibrium mean-variance strategy

We study a dynamic mean-variance portfolio optimization problem under the reinforcement learning framework, where an entropy regularizer is introduced to induce exploration. Due to the time–inconsistency involved in a mean-variance criterion, we aim to learn an equilibrium policy. Under an incomplete market setting, we obtain a semi-analytical, exploratory, equilibrium mean-variance policy that turns out to follow a Gaussian distribution. We then focus on a Gaussian mean return model and propose a reinforcement learning algorithm to find the equilibrium policy. Thanks to a thoroughly designed policy iteration procedure in our algorithm, we prove the convergence of our algorithm under mild conditions, despite that dynamic programming principle and the usual policy improvement theorem failing to hold for an equilibrium policy. Numerical experiments are given to demonstrate our algorithm. The design and implementation of our reinforcement learning algorithm apply to a general market setup.     

我国省际旅游业包容性增长的指标体系及聚类分析

中国旅游业经历了多年的高速增长,但增长方式属于粗放型。旅游业应发挥"保增长、扩内容、调结构、惠民生"功能,实现包容性增长。关注国民福利的改善和提升,实现旅游业与社会、经济、文化、环境的协调发展。     

钢铁上市公司财务绩效评价与对策分析

采用主成分分析法对我国钢铁上市公司2006年的财务绩效进行了综合评价,并分析了引起绩效优劣的动因。研究表明：2006年钢铁上市公司的综合财务绩效整体较好,仅个别企业表现不佳;大部分企业的财务核心能力接近,两端企业差异较大;财务管理的目标呈内外两极分化。同时,提出了钢铁上市公司提高财务绩效的对策。     

文化产业关联特征的动态分析——基于广东省2002年和2007年的投入产出数据

文化产业已上升为我国的战略性新兴产业,加强对文化产业的产业关联度及其经济影响力研究,对于制定政策措施,进一步发展文化产业,推动产业结构升级有重要意义。现有的基于投入产出分析的文化产业发展研究,绝大部分都只是分析了文化产业对国民经济的影响力和感应度,并没有分析文化产业在最初投入和最终使用中的构成情况,也没有进行动态比较研究,而且在文化产业的具体外延界定方面也存在着不足。本文在前人研究的基础上,将文化产业分为文化品制造业和文化服务业,以广东省2002年和2007年的投入产出数据为例,分别研究了广东文化产业的中间需求、最终使用和增加值的构成,以及文化产业对广东省国民经济的影响力和感应度,同时考虑2002年到2007年的动态变化,更加全面深入地分析了广东文化产业的产业关联动态特征。研究发现广东文化品制造业呈现出＂高影响力、低感应度＂的终端型产业特征,文化服务业则呈现出＂低影响力、低感应度＂的最终需求导向型特征。     

关中地区城市化水平地域差异及影响因素分析

将陕西省关中地区近25年的城市化进程分为三个阶段,从人口、社会经济、地理环境等角度构建评价指标体系,在不同的阶段利用灰色关联方法分析影响关中地区城市化水平地域差异的主要因素,并根据贡献度进行排序,找到了在近25年中影响关中地区城市化水平地域差异的重要因素.     

物流企业的电子商务拓展探析

电子商务将以不可阻挡之势渗入物流业，物流是实施电子商务的根本保证，电子商务对物流企业的影响日益明显。物流企业应主动应对电子商务带来的新挑战．采取有效措施．积极拓展电子商务。本文着重论述了物流企业拓展电子商务的具体措施．并阐述了物流企业拓展电子商务应注意的若干问题。     

试析农民专业合作社的财务信息质量

财务信息的产生与优化主要是在信息供给双方的合力作用下形成的。当前,由于利益相关者没有信息需求的要求,农民专业合作社的财务信息需求动力弱化;而农民专业合作社的经营管理人员,出于控制成本等方面的要求,对于财务信息的供给也没有热情,政府监管和社会审计工作对于农民专业合作社的财务信息也无暇顾及。供需双方需求动力弱化的情况下,农民专业合作社的财务信息质量必然难以保证,财务管理工作也难以开展。     

Environmental Valuation with Imperfect Information The Case of the Random Utility Model

This paper considers welfare analysis with therandom utility model (RUM) when perceptions ofenvironmental quality differ from objectivemeasures of environmental quality. Environmental quality is assumed to be anexperience good, so that while perceptions ofquality determine choices, ex postutility is determined by objective quality. Given this assumption, I derive a measure ofthe welfare impact of changes in environmentalquality, and I show how this new welfaremeasure differs from the traditional welfaremeasure developed by Hanemann (1982). This newwelfare measure provides an approach tomeasuring the value of information aboutenvironmental quality within the framework ofthe random utility model.     

Exploring the impact of economic integration agreements through extreme bounds analysis

This article provides an empirical strategy guided by the data to estimate the effects of Economic Integration Agreements (EIAs) on trade flows and their transitional dynamics. The strategy uses Extreme Bounds Analysis (EBA) to guide the choice of lags and leads in the effects without researchers' discretion involved. We show that arbitrarily selected year intervals and starting year can result in non-robust estimates of transitional dynamics of the effects of EIAs on trade flows. The empirical strategy follows two steps: EBA first sifts lags and leads of EIAs robustly related to trade flows from candidates, then these are included in the gravity equation to estimate the effects of EIAs on trade. We find that various lags and leads are robustly and positively related to trade flows, and the lag and lead structure depends on the level of integration. Our results show that EIAs have a long-term effect of 63% on trade flows. Under the richer lag and lead structure, deep-integration agreements beyond the level of free trade agreements have a much higher impact on trade flows than free trade agreements do (132% vs 31%). The estimates of effects of EIAs obtained from EBA-based estimation have a smaller contemporaneous effect and larger phased-in effects compared to previous studies relying on the subjective choices of year intervals while similar results are observed with the decomposed EIAs.     

中国大陆各地区城市化发展水平的统计分析

利用2008年中国大陆31个地区的数据,从经济、公共服务、城建和人口等四个因素出发,运用因子分析和系统聚类的方法建立各地区城市化发展水平评价指标体系。结果显示：中国大陆整体城市化发展水平还有待提高,地区间城市化发展水平差距较明显,城市化各方面的因素水平发展不平衡。应在大力发展城市基础设施建设的基础上,发挥优势地区的带动作用,促进城市化水平协调发展。