Asymmetric volatility in the foreign exchange markets

We examine the presence or absence of asymmetric volatility in the exchange rates of Australian dollar (AUD), Euro (EUR), British pound (GBP) and Japanese yen (JPY), all against US dollar. Our investigation is based on a variant of the heterogeneous autoregressive realized volatility model, using daily realized variance and return series from 1996 to 2004. We find that a depreciation against USD leads to significantly greater volatility than an appreciation for AUD and GBP, whereas the opposite is true for JPY. Relative to volatility on days following a positive one-standard-deviation return, volatility on days following a negative one-standard-deviation return is higher by 6.6% for AUD, 6.1% for GBP, and 21.2% for JPY. The realized volatility of EUR appears to be symmetric. These results are robust to the removal of jump component from realized volatility and the sub-samplings defined by structural-changes. The asymmetry in AUD, GBP and JPY appears to be embedded in the continuous component of realized volatility rather than the jump component.     

基于引力模型的中美农产品贸易边境效应研究

针对中美两国在农产品贸易上的新变化,应用引力模型的派生模型——边境效应引力模型对中美两国农产品贸易的流量和流向进行理论和实证研究。首先介绍了边境效应引力模型基本模型的推导过程,并引入了调整模型。然后采用1987至2005年其中5年的截面数据进行计算,结果发现:中美农产品贸易的边境效应显著存在,且呈逐年下降趋势;两国之间的农产品贸易边境效应存在流向和区域上的差异;距离的平方并不影响模型的可靠性。     

CALL及其制约因素刍议

当今世界,计算机已被广泛应用于语言教学。计算机辅助语言教学经历了行为主义的计算机辅助语言教学、交际的计算机辅助语言教学和整体的计算机辅助语言教学三个主要阶段。运用计算机辅助语言教学有助于激发学生的学习动机,为学生提供真实的学习材料,促进学生进行更广泛的相互交流活动,提高学生的个体化学习能力,鼓励学生从单一信息源中脱离出来,促进全球化的共识等。但是,计算机辅助语言教学也有其制约因素,文章从财政困难、计算机软件和硬件的可利用性、技术与理论方面的障碍以及技术的接受等四个方面对此进行了阐述。     

美国钢铁贸易保护争端及其对世界经济贸易的影响

美国钢铁保障措施的出台是经济衰退期外贸政策保护主义倾向进一步加强的具体表现。作为WTO成员，美国按国内法201条款实施的钢铁保障措施必须符合WTO保障措施规则。但美国钢铁保障措施即使符合WTO规则，也是通过损害其钢铁贸易伙伴正当利益来追求本国利益最大化。因此，在全球贸易体制约束下，美国的行为必然引起各相关方与美国之间运用全球贸易规则的利益博弈，并由此对世界经济贸易产生重大影响。     

钱包赌戏悖论及其行为的经济学意义

本文对行为经济学的一个重要微观模型———钱包赌戏悖论建立了认知分析框架 ,不仅彻底消解了该悖论 ,还发现了与效用和概率均无关的一种新的非理性效应。这一效应既可能导致无帕累托效率的交易陷阱 ,也可能与效用歧化和概率误判等已知的行为经济学效应协同作用 ,产生更复杂的非理性决策。     

From T-Bills to Stocks: Seasonal Anomalies Revisited

This paper employed eleven data series which consist of stocks, bonds, bills, equity premiums, term premiums, and various default premiums to investigate whether January seasonality reported in existing literature is robust across different states of the economy as this has important trading implications. For the periods 1926–1990, small stocks, small stock premiums, low grade bonds, and default premiums (spread between high grade, low grade and government bonds) reveal January seasonality and that the seasonality is robust across different states of the economy except for low grade bond returns and default premiums. January seasonality for low grade bond returns and low grade bond default premiums are primarily driven by results found during periods of economic expansion. Overall, January seasonality is more evident during the economic expansion periods although the magnitude of default premiums is larger during periods of economic contraction. Furthermore, prior findings of strong summer equity returns are primarily driven by the results found during the periods of economic contraction. It is also found that equity returns are generally higher during periods of economic expansion.     

Dominance Statistics: A Simulation Study on the d Statistic

Quality &; Quantity - Cliff (1993) has proposed the use of a measure of effect size alternative to traditionalmean differences: δ {? = Pr(xi1 &;gt; xj2) - Pr(xi1 &;lt; xj2)}which,...     

封闭式基金的市场流动性研究

本文在给出一个改进流动性指标的基础上 ,利用该指标对封闭式基金的市场流动性进行了分析。研究发现 :封闭式基金市场流动性不存在周内效应 ,周内也无显著的变动模式 ;封闭式基金流通股本规模对市场流动性有显著影响 ,市场偏好次小盘基金 ;封闭式基金市场流动性总体上对基金折价没有显著影响。     

对供应链中"牛鞭效应"综合治理策略的探讨

通过文献综述,讨论了供应链中牛鞭效应的现象和成因，提出了减轻和消除该效应的对策以及进一步研究方向。     

YAWL语言及其系统的初步研究

工作流和工作流管理系统的合理应用可大大提高办公自动化的程度,而现有的工作流系统在支持工作流基本模式上存在一定的缺陷。一种新出现的YAWL语言较好地支持了工作流现有的基本模式,文章就YAWL语言及其系统的执行方法进行了初步的研究。