金融危机应对政策的淡出与改革方向的研判

面对全球金融危机,我国政府采取了积极的财政政策和宽松的货币政策,从现实情况看,金融危机应对政策实现了＂保八＂的历史任务。进入后危机时代,如果把金融危机应对政策常态化容易造成新的经济问题。面对全球中央银行加息,我国也逐步淡出危机政策。值得注意的是,金融危机应对政策的淡出要与加快改革相结合,以改革突围实现经济的可持续发展。     

长期资产减值准备:盈余质量与市场反应

对2001～2006年旧资产减值会计制度实施期间的相关数据进行检验,本文发现长期资产减值准备所产生的应计盈余明显地降低了会计盈余的质量。按长期资产减值准备的应计盈余所构建的逆向套利组合能获得显著的超额报酬率,长期资产减值准备的应计盈余与超额回报负相关,说明市场不能识别长期资产减值准备对会计盈余质量的影响。本文的结论支持新会计准则禁止长期资产减值准备转回的规定。     

An inexact l2-norm penalty method for cardinality constrained portfolio optimization

Abstract

We analyze and solve a single-period portfolio optimization problem with non-convex constraints, which address practical concerns of investment such as the active share weights of sectors and the number of stocks held in a portfolio. We reformulate the problem to simplify the computation and propose an inexact l₂-norm penalty method to solve the problem.     

基于全国一张网的天然气基础设施经营模式创新探索——中国天然气管网运营机制研究之三

结合国家石油天然气管网集团有限公司正式运营一年以来天然气行业的发展情况,分析中国天然气上中下游各环节所面临的主要痛点,探索天然气基础设施的商务模式创新.一是提出国家管网集团运营的天然气储运设施基本形成了天然气全国一张网的物理架构,以此为基础可以构建一个大跨度的天然气大宗商品物流系统,包括管输、储存、加工和配送4个子系统;二是立足发挥全国一张网的网络优势和储运一体化运营整体优势,创新提出了跨空间转移、跨时间转移、气液相态转换、商业储备、服务产品组合等商业模式,并通过建立全国性的天然气储运能力交易平台、天然气物流调度平台和天然气商品交易平台,实现天然气资源的灵活、高效和安全输配.     

数字经济对区域经济高质量发展的影响研究

推动数字经济发展,是我国在当下推动经济转型,促进高质量发展的重要战略。本文基于2012~2019年省级面板数据,构建双向固定效应模型,运用基准回归、异质性检验和分位数回归的方法进行实证研究发现,数字经济助推经济高质量发展的同时还存在地区差异,对西部影响最大,中部影响最小,而数字经济的发展水平又受到产业结构、技术创新等因素影响。因此,本文针对不同地区差异分别提出建议,从而促进持续更新发展理念,以创新驱动发展,优化产业结构为数字经济提供良好环境,以期推动数字经济建设发展。     

Political hazards and entry modes of Chinese investments in Africa

Africa has achieved the fastest growth rate of inward foreign direct investment (FDI) recently. Yet heightened political hazards present substantial challenges to foreign firms in Africa. This study examines the entry strategies that firms may take to mitigate such hazards by exploring the relationship between political hazards and entry mode choices in Africa. We further consider how an investing firm’s host country experience and foreign aid provided by its home country government to host countries in Africa can influence this relationship. In a sample of listed Chinese firms’ investments in Africa from 2000 to 2014, we find that Chinese firms tend to use the joint venture mode when political hazards are high in an African country. This relationship is weakened when they accumulate host country experience and when the Chinese government’s foreign aid to an African country increases. Our findings point to firm-level strategies to mitigate political hazards as well as instruments available to home country governments to help their multinational firms operating in host countries characterized by unstable political environments.     

Diffusion of mobile telephony: An empirical study in Taiwan

Mobile telephony penetration is a major indicator of mobile telephony diffusion. Taiwan had a mobile telephony penetration of 108% in 2002, ranking first in the world. This study analyzes this accelerated diffusion in terms of growth model and determinants of the diffusion rate. To eliminate the inherent uncertainty associated with choosing the optimal growth model, this study compares the performance of three conventional models, namely Gompertz, Logistic and Bass, to identify the most appropriate model, and to distinguish the forces driving the diffusion rate. Empirical results indicate that the most appropriate model is the Logistic model. Network externalities, which this study shows to be the same as the imitation effect in the Bass model, explain the superiority of the Logistic model. Moreover, market competition, which markedly reduces service prices, is identified as a primary driver of the diffusion rate of mobile telephony in Taiwan. Economic conditions, technological innovation and number of operators are insignificant factors. Finally, mobile telephony is a substitute for fixed-line telephony in Taiwan.     

山东地区城市天然需求负荷与气温关系研究

作为清洁能源的天然气,近年来在山东的销售量持续增长.天然气的负荷需求主要受地区气象条件、工业企业生产情况、居民生活习惯、价格水平、节假日等多种因素的影响,其中气温是造成城市天然气短期负荷波动的主要原因之一.本文研究山东省天然气市场需求量与气温之间的关系,对天然气日均负荷进行周期分析,找出天然气日均负荷变化与日均气温之间的相关关系,为天然气公司进行地区性天然气计划平衡决策提供基础信息参考.     

大鼠脑缺血后缺血区VEGF表达变化及通心络的影响

目的观察大鼠脑缺血后缺血区VEGF mRNA及蛋白水平随时间表达的变化及通心络对其的影响。方法制备大鼠大脑中动脉梗塞局灶性脑缺血模型,采用RT—PCR法及免疫组化法检测脑缺血后每组实验动物不同时间缺血区VEGFmRNA及蛋白表达的变化以及通心络的作用。结果1、正常大鼠脑缺血后脑组织中VEGFmRNA表达很少,大鼠局灶性脑缺血后VEGF mRNA表达逐渐增强,3d达高峰,缺血7d后叉降至约正常水平。VEGF主要在神经元阳性表达,表达趋势与mRNA基本吻合。2、通心络高剂组VEGF mRNA表达显著增强（p〈0.01,p〈0.05）;通心络各组vEGF阳性神经元数量增加：结论局灶性脑缺血可促进缺血区内源性神经保护因子VEGF高表达;通心络可增强和延长缺血区VEGF高表达,发挥对脑缺血的保护作用.