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.     

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.     

通胀预期与货币需求:实际调整与名义调整机制检验

货币存量调整机制一般可分为两类设定方式:实际调整过程和名义调整过程.在实际调整机制下,预期通胀对货币需求没有独立的影响,而在名义调整机制下,通胀预期自然成为货币需求的一个解释变量.通胀预期在货币需求函数中显著可能并不意味着通胀预期直接影响了货币需求,而是表明了部分调整机制的误设.本文根据预期通胀率在货币需求函数中的显著性,比较了货币持有量名义调整和实际调整机制假说对我国的解释能力,认为名义机制比实际机制更好地描述了中国的经验.我们在一个状态空间中联合估计预期通胀以及货币需求方程,避免了传统"两步法"的不足.     

Developing land use and transport PSS: Meaningful information through a dialogue between modelers and planners

One of the key barriers to integration of land use and transport planning is the lack of a “common language” (i.e. tools, instruments, indicators) that can support planners from both domains in developing shared visions and integrated strategies. Many of such tools and indicators have been developed in recent years, but not so many are implemented in practice. In this paper a new, participatory development approach for planning support systems (PSS) is proposed, termed “mediated planning support” (MPS) that addresses bottlenecks blocking this implementation. It is founded on insights from knowledge management, system dynamics and software innovation and is applied in the Greater Region of Amsterdam. This paper discusses the evolution of the PSS, highlighting the most useful elements which can be applied in other land use and transport planning projects. It offers insights for practitioners and researchers interested in land use and transport planning integration and for professionals that are dealing with supporting planning with information and technologies.     

Nowcasting China’s GDP Using a Bayesian Approach

Real time nowcasting is an assessment of current-quarter GDP from timely released economic and financial series before the GDP figure is disseminated. Providing a reliable current quarter nowcast in real time based on the most recently released economic and financial monthly data is crucial for central banks to make policy decisions and longer-term forecasting exercises. In this study, we use dynamic factor models to bridge monthly information with quarterly GDP and achieve reduction in the dimensionality of the monthly data. We develop a Bayesian approach to provide a way to deal with the unbalanced features of the dataset and to estimate latent common factors. We demonstrate the validity of our approach through simulation studies, and explore the applicability of our approach through an empirical study in nowcasting the China’s GDP using 117 monthly data series of several categories in the Chinese market. The simulation studies and empirical study indicate that our Bayesian approach may be a viable option for nowcasting the China’s GDP.     

Estimation of zero-intelligence models by L1 data

A unit volume zero-intelligence (ZI) model is defined and the distribution of its L1 process is recursively described. Further, a generalized ZI model allowing non-unit market orders, shifts of quotes and general in-spread events is proposed and a formula for the conditional distribution of its quotes is given, together with a formula for price impact. For both the models, MLE estimators are formulated and shown to be consistent and asymptotically normal. Consequently, the estimators are applied to data of six US stocks from nine electronic markets. It is found that more complex variants of the models, despite being significant, do not give considerably better predictions than their simple versions with constant intensities.