Scaledt分布、杠杆效应和上证综指的VaR风险

与正态分布相比，上证指数收益率的经验分布具有尖峰厚尾特征，但用Scaled t-分布比正态分布可以更好地拟合上证指数收益率的经验分布。本文以Scaled t-分布假设下的GJR模型为基础，测量了上证指数收益率波动性的杠杆效应，即信息对波动性的不对称影响：并根据GJR模型应用Monte Carlo模拟方法，测定上证指数日收益率和持有期收益率的风险价值（VaR）。根据GJR模型提供的结果，上证指数30天、60天和90天持有期收益率的风险值分别为12．1％、17．8％、22．0％。用GJR模型比均值-方差模型和历史模拟方法计算的5％显著性水平VaR值更接近实际收益率。     

Crossing spatial analyses and livestock economics to understand deforestation processes in the Brazilian Amazon: the case of São Félix do Xingú in South Pará

The Amazon is the largest tropical forest area on Earth, and has been undergoing rapid deforestation for the last four decades. In the Brazilian Amazon, large‐scale pasture for cattle ranching and soybean production are the main land uses, leading to a yearly deforestation rate of 0.5%. These conversions are mostly located in frontier areas distributed along the so‐called “arc of deforestation”. Within this large zone, various land use change processes are interacting through several modes of land valuation and organisation. From several case studies in the State of Pará (Brazil), the current project aims at analysing how landscape dynamics are related to infrastructure development, ecological conditions, zoning policies and to the evolution and the organisation of the production, consumption and marketing chains of livestock products. This paper presents the results for one test site, the region of São Félix do Xingú, South of Pará This region is the focus of land speculation, cattle expansion, and deforestation. Road construction, investments in electrical energy, financial credit for cattle, and the land reform policies have all fuelled this process. All these factors make this region one of the most dynamic agricultural frontiers in the Brazilian Amazon. The main objective of the paper is to improve our understanding of deforestation processes by crossing spatial analyses and 1ivestock economics.studies, and to characterise the role and impact of various natural and anthropic factors in the location and development of the main types of farmers, and their policy implications.     

A consumer education programme based on the Transtheoretical Model of Change

MONEY 2000? is a successful consumer education programme that was implemented by Cooperative Extension personnel in over two dozen states of the USA between 1996 and 2002. One of the unique features of this programme is that it was based on the Transtheoretical Model of Change (TTM), a framework that has been widely used to study health‐related behaviour changes such as smoking cessation. This paper first describes how the MONEY 2000? programme was developed around major constructs contained within the TTM. Findings are reported from a survey conducted with participants in the first two states that delivered the programme. The findings suggest that several change processes used by MONEY 2000? participants are associated with specific stages of change. In addition, there may be differences in behavioural changes between participants who increased their savings and those who reduced their debts.     

CROSS‐DOCKING AND ITS IMPLICATIONS IN LOCATION‐DISTRIBUTION SYSTEMS

Cross‐docking replaces traditional warehousing, enabling continuous flow of items without storage. Here we model location‐distribution networks, that include cross‐docking facilities, to obtain the latter's impact on the supply chain. We formulate optimization models to minimize total cost in three multi‐echelon networks, each model generalizing the preceding one. The first includes a single manufacturer, one product type, and multiple customers. Cross‐docks are to be located between origin and destinations. Besides solving optimally, a tool for quantitative analysis of direct‐shipment decisions is developed. The second model considers more than one product: We determine a cost‐effective sequence of items for indirect shipment (via cross‐docks). Finally, in a network with multiple origins, optimal solutions are obtained for 40 medium‐sized and larger examples.     

A Pricing and Hedging Comparison of Parametric and Nonparametric Approaches for American Index Options

This article investigates the extent to which options on theAustralian Stock Price Index can be explained by parametricand nonparametric option pricing techniques. In particular,comparisons are made of out-of-sample option pricing performanceand hedging performance. The dataset differs from many of thoseused previously in the empirical options pricing literaturein that it consists of American options. In addition, a broaderspectrum of techniques are considered: a spline-based nonparametrictechnique is considered in addition to the standard kernel techniques,while the performance of a Heston stochastic volatility modelis also considered. Although some evidence is found of superiorperformance by nonparametric techniques for in-sample pricing,the parametric methods exhibit a markedly better ability toexplain future prices and show superior hedging performance.     

采取网络型的政府市场供给模式应对房价问题

面对不断飙升的房价,从理论界到政策层面对其原因都有不同的解读,但从实践结果来看对房价的治理并不理想。本文在综合分析理论研究与国家调控政策的基础上,认为创新措施采取网络型的政府市场供给模式是解决房价过快上涨的有效途径。文章着重对这一模式进行了分析,并认为此举对缓解供需矛盾、解决市场的信息不对称、市场操控、改变预期、稳定房价等都有非常重要的作用。     

Spatial determinants of Japanese FDI in China

Research on foreign direct investment in China has spawned an increasingly large literature. Whilst regional cleavages with respect to the distribution of foreign direct investment (FDI) are acknowledged, empirical research on the spatial determinants of FDI in China has been limited. Furthermore, research on the spatial determinants of home country FDI in China has thus far been neglected due to difficulties in accessing the appropriate data. The objective of this paper is to examine the spatial determinants of Japanese direct investment in China by using an econometric model. To that purpose, a dataset is created from the Toyo Keizai directory on the overseas activities of Japanese companies. The results show that tertiary education, inland waterways, as well as coastal location are positive and significant determinants of Japanese investment in China.     

城市圈可接近性与城市经济增长——以珠三角、武汉城市圈为例

针对我国目前正在兴起的建设城市圈的热潮,本文讨论了城市圈形成的一个模型,运用空间计量以及面板数据的方法对我国已经发展较成熟的珠三角城市圈以及正在建设的武汉城市圈进行了比较研究,结果发现:城市圈的可接近性能显著地促进位于城市圈内的城市的经济增长水平。本文还提出了发展边缘城市、实施组团式发展的城市圈发展策略。     

国内外企业技术创新策略的博弈分析

入世后我国企业面临着国外企业日益加强的竞争压力，技术创新成为企业的重要选择。本文从技术创新成本的角度，建立了国内企业与国外企业技术创新竞争的静态博弈模型，根据模型，当国外企业以规模扩张为竞争目标时，我国企业只能选择渐进式的技术创新战略。     

Contemporary Extensions of the Rasch Model

This paper will introduce, discuss and illustrate two contemporary extensions of theRasch model: the one parameter logistic model (Verhelst and Glas, 1995) and theMultidimensional Rasch model (Hoijtink et al., 1999). Using data with respect tothe measurement of schizotypy (Vollema and Hoijtink, 2000) the most importantfeatures of both models will be illustrated. For the one parameter logistic modelthese include: a (discrete) discrimination parameter for each item; a test for itembias; and, estimation of the location of a person on the (latent) trait that is beingmeasured. For the multidimensional Rasch model these include: specification ofthe model; and, model selection. All analyses presented in this paper can be executedusing either OPLM (Verhelst et al., 1995), TESTFACT (Wilson et al.,1984) or ConQuest (Wu et al., 1998). At the end of the paper some features ofmodels and software that have not been discussed will be summarized.