Contemporaneous intraday volume, option, and futures volatility transmissions across parallel markets

The primary objective of this article is to investigate volatility transmission across three parallel markets operating on the Sydney Futures Exchange (SFE), both within and out of sample. Half-hourly observations are sampled from transaction data for the share price index (SPI) futures, SPI futures options, and 90-day bank accepted bill (BAB) futures markets, and the analysis is carried out using the simultaneous volatility (SVL) system of equations as well as competing volatility models. The results confirm the poor ability of GARCH models to fit intraday data. This study also applies an artificial nesting procedure to evaluate the out-of-sample volatility forecasts. Implied volatility has very limited (if any) predictive power when evaluated in isolation, whereas the SVL model with implied volatility embedded provides incremental information relative to competing model forecasts.     

Lithuania's food demand during economic transition

The linear approximate version of the almost ideal demand system (LA‐AIDS) model is estimated using data from the Lithuanian household budget survey (HBS) covering the period from July 1992 to December 1994. Price and real expenditure elasticities for 12 food groups were estimated based on the estimated coefficients of the model. Very little or nothing is known about the demand parameters of Lithuania and other former socialist countries, so the results are of intrinsic interest. Estimated expenditure elasticities were positive and statistically significant for all food groups, while all own‐price elasticities were negative and statistically significant, except for that of eggs which was insignificant. Results suggest that Lithuanian household consumption did respond to price and real income changes during their transition to a market‐oriented economy.     

黑龙江干流水电梯级开发对鱼类资源

分析了黑龙江干流水电梯级开发对鱼类资源的影响,结果表明,梯级水利枢纽建成后,对鲤、鲫、在型鱼类的影响利弊兼有。作用不明显;对以鲢、草鱼为代表的半洄游型鱼类产生的不利影响较大;对鲟、鳇、大麻土产持产鱼类的不利影响较明显。     

Coupling urban expansion models and hydrological models: How important are spatial patterns?

It is well known that urban expansion has a severe impact on the surface water balance by transforming vegetated covers into sealed surfaces. This transformation causes changing fluxes of evapotranspiration, surface runoff and groundwater recharge. In order to estimate the impact of land cover changes on the surface hydrology, hydrological models are often coupled with different types of land cover change models. It is, however, not clear to what extent spatially-explicit urban expansion scenarios provide an added value in comparison with non-spatial urban expansion models at different scale levels. The objective of this paper is to acquire a better insight in the importance of scale effects involved in the coupling of urban expansion scenarios and hydrological models. The relative importance of using different projections of both (i) quantity and (ii) spatial patterns of urban expansion was analysed at four different scale levels. The highly urbanised Flanders–Brussels region was taken as an example application. Twelve different urban expansion scenarios for 2025 and 2050 were developed and subsequently used as an input in a spatially-distributed water balance model. The results obtained suggest that at the level of the Flanders–Brussels region, an accurate estimation of the quantity of urban expansion should get priority over an accurate projection of the spatial patterns. However, the importance of using accurate projections of the spatial pattern of urban expansion increases systematically at local scale levels. A uniform strategy for coupling urban expansion models and hydrological models thus seems inappropriate. These findings are highly relevant for water management and spatial planning policymakers that typically operate at different administrative levels.     

What does a small corporate effect mean? A variance components simulation of corporate and business effects

In a widely cited paper, Rumelt (1991) presents estimates of the relative influence of corporate, business unit, and other influences on business unit profitability and finds the corporation explains almost none of the variability in business unit profitability. Using a Monte Carlo simulation, we examine the relation of variance component magnitudes to other indicators of the importance of a particular effect. Our results demonstrate that variance components can be an extremely nonlinear indicator of importance. We also question whether Rumelt's corporate effect represents the possible contributions of corporate strategy to business unit performance. This addresses a puzzle raised by Rumelt (1991) concerning the small effect of corporations in explaining performance, and suggests that Rumelt's findings should not be seen as demonstrating the insignificance of corporate strategy. © 1997 John Wiley & Sons, Ltd.     

Role of network structure and network effects in diffusion of innovations

Why does diffusion of innovation sometimes propagate throughout the whole population, and why at other times does it halt in its interim process? The current paper provides a potential answer to this question by developing a simple computational model of social networks. The proposed computational approach incorporating small-world graphs enables the authors to find that diffusion of innovation is more likely to fail in a random network than in a highly clustered network of consumers. A marketing implication is that the choice of initial target groups and their network structures matter in influencing whether an innovation makes full or partial penetration, in markets where network effects plays a role.     

制度环境、激励结构与垄断行业收入规范

文章将转轨经济条件下制度及经济环境随机变动的因素引入分析中,并将收入合同作为管制者与经营者之间策略互动的一个内生结果。特定制度环境导致的垄断厂商经营者面临不确定性的扩大以及国有产权下管制者与经营者贴现因子的差异使我国垄断行业厂商经营者有更大的动力攫取制度设计中的信息租金。认为在垄断性行业改革中更多的强调绩效考核及引入专家式监管对我国垄断性行业收入规范改革有着重要的作用。     

Pricing with customer recognition

This article studies the dynamic effects of behaviour-based price discrimination and customer recognition in a duopolistic market where the distribution of consumers' preferences is discrete. Consumers are myopic and firms are forward looking. In the static and first-period equilibrium firms choose prices with mixed strategies. When price discrimination is allowed, forward-looking firms have an incentive to avoid customer recognition, thus the probability that both will have positive first-period sales decreases as they become more patient. Furthermore, an asymmetric equilibrium sometimes exists, yielding a 100–0 division of the first-period sales. As a whole, price discrimination is bad for profits but good for consumer surplus and welfare.     

滚子加热炉温度均匀度对结果的影响及改进措施

滚子加热炉是将钻井液加热老化的专用设备,在钻井液添加剂产品的质量检验中也普遍的使用。滚子加热炉的要害是内部温度分布的均匀性和显示温度的真实性,直接影响到产品检测指标的重现性和质量判断的准确性。目前国内各实验室普遍使用的国产多轴滚子加热炉,不同程度地都存在各轴区温度分布差异大的问题。使得同一试验浆放在同一滚子加热炉内的不同轴区,老化后检测出的数据差距很大,极易造成误判,引起质量争议。我们对我公司所用滚子加热炉进行反复研究、测试和改造。使炉内温度高低差缩小到5℃以下,钻井液试验和产品检验数据重现性好,有效地促进了产品质量的稳定工作。