Nonlinear analysis for forecasting currencies: are they useful to the portfolio manager?

The importance of a time-varying specification for both the return and the risk of financial assets is well known. The purpose of this study is to investigate if some of the most recently developed econometric models, combined with technical indicators often used by practitioners, can significantly predict future returns. While most studies have focused on either univariate series or in-sample analyses of a given econometric specification, this study considers a multivariate framework where a US based investor daily reallocates a portfolio of three currencies (Deutschmark, Swiss Franc and Japanese Yen). Series of three years out-of-sample forecasts are analysed in terms of risk and return and it is shown that some of the tested speciications can indeed signiicantly predict future daily returns and correlations over this three-year period.     

Some Reflections on the Spatial Dimensions of Occupational Segregation

This paper considers the role that urban spatial structure may play in the process of occupational segregation, and argues that neoclassical economic models of urban employment and residential location decisions have not considered the relationship between gender-based labor market status and space. The paper provides a critical feminist perspective on how conventional urban models have been used to explain patterns of segregation, and suggests reasons for limitations in existing theoretical and empirical analysis. It also explores ways in which economists can draw on work in other disciplines to develop fuller and more useful models of the relationship between urban spatial structure and occupational segregation.     

Reforming Social Security in a Transition Economy: The Case of Lithuania

This paper points out a number of problems associated with the existing pension system in Lithuania. Reforms are proposed, including (i) a substantial increase in the basic pension benefit rate, financed on a pay-as-you-go basis, provided universally, and regulated according to wage/price indexation; (ii) a significant cut in the tax contribution rate to the public pension system matched by a rise in the VAT; (iii) a rise in the retirement age to 65 for both men and women; and (iv) a gradual conversion to a private, funded, mandatory pension system to replace the earnings-related part of the current pension system.     

Efficiency tests with overlapping data: an application to the currency options market

This paper presents the results of an empirical study into the efficiency of the currency options market. The methodology derives from a simple model often applied to the spot and forward markets for foreign exchange. It relates the historic volatility of the underlying asset to the implied volatility of an option on the underlying at a specified prior time and then proceeds to test obvious hypotheses about the values of the coefficients. The study uses panel regression to address the problem of overlapping data which leads to dependence between observations. It also uses volatility data directly quoted on the market in order to avoid the biases which may occur when ‘backing out’ volatility from specific option pricing models. In general, the evidence rejects the hypothesis that the currency option market is efficient. This suggests that implied volatility is not the best predictor of future exchange rate volatility and should not be used without modification: the models presented in this paper could be a way of producing revised forecasts.     

国际贸易与劳工标准挂钩的模式比较研究

虽然在世界贸易组织框架内是否将国际贸易和劳工标准挂钩争论激烈,但由于该问题的现实性,国际贸易与劳工标准挂钩已出现多种实现模式并存的局面。文章对现有的国际贸易和劳工标准挂钩的主要模式从约束性、经济性和有效性方面进行了比较研究,认为各种模式有其特点和适用范围,模式发展的近期方向将是ILO和WTO的充分合作模式。     

长白山区作物气候生产力及其地理分布的研究

本文建立了长白山区玉米、水稻和大豆的气候可能产量模式和地理分布模型,计算了各地的气候生产潜力,并进行了地形影响订正。结果表明,长白山区主要农作物气候生产力的地理分布特征主要取决于地势、地形和经度,气候生产力随着海拔的升高按照三次抛物线函数递减,随着经度的升高按照线性函数递减。主要山体的南、西南坡气候生产力较高,北、东北坡气候生产力较低。该项研究为长白山区农业立体开发提供了综合气候生态依据。     

亚洲地区股票指数收益率的波动性研究——基于GARCH族模型

为防范股票市场上的不确定性和风险,有效地度量股票指数收益率的波动性显得尤为重要。本文运用GARCH族模型,拟合了股票指数收益率的波动性方程,并实证研究了亚洲地区四个最具代表性国家:日本、中国、印度和韩国的股票指数收益率的波动性。结果表明:亚洲地区股票指数收益率的波动呈现出聚集性和持续性,股票市场存在着冲击的非对称性;中国和印度的股票市场抗风险能力比日本和韩国弱,股票指数收益率的波动性带来的负面影响更大。     

国外小额保险经营模式比较及其对我国的启示

小额保险是增强穷人抵御风险冲击能力、减轻贫困的重要手段。全球范围内小额保险的经营模式主要包括互助或合作保险模式、合作-代理模式及独立经营模式。从国外小额保险的发展实践来看,小额保险的经营模式存在着较大的差异性,这种差异性与各国或地区的社会经济条件、发展阶段及制度环境等的不同密切相关。互助或合作保险模式、合作-代理模式与独立经营模式各自有其自身的优势和劣势。比较分析国外小额保险经营模式的具体特点对我国发展小额保险有着良好的启示。     

Efficient choice set designs for estimating availability cross-effects models

Batsell and Polking proposed a discrete choice model which incorporates the availability (presence or absence) of competing brands into the utility of each brand under study. The information on relative impacts of adding or deleting brands is of strategic interest, and models that do not incorporate such effects may be misleading. The designs suggested by Batsell and Polking have 2^m–m–1 choice sets. Even with as few as 10=m brands, this requires over 1000 choice sets. In this paper we provide a catalog of designs for estimating cross effects models in as few as 2m–1 choice sets. This will make cross effects modelling practical in a wide range of academic and commercial settings.     

国内上市公司债务融资效率的实证分析

经典公司理论表明,作为硬约束,债务融资能够在一定程度上降低公司内在的代理成本,从而提高公司经营效率。文章利用上海证券交易所A股上市的522家上市公司2003-2008年的财务报表相关数据对此做一个实证研究。时间固定效应模型回归的结果显示,我国上市公司的资产收益率与债务融资率之间呈负相关关系,国内上市公司的债务融资并不能有效控制经营者为最大化自身收益而采取的机会主义行为,代理成本的存在一定程度上降低了公司经营效率。