Valuation, optimal asset allocation and retirement incentives of pension plans

We provide a framework in which we link the valuation and assetallocation policies of defined benefits plans with the lifetimemarginal productivity schedule of the worker and the pensionplan formula. In turn, we examine the retirement policies thatare implied by the primitives of the model and the value ofpension obligations. Our model provides an explicit valuationformula for a stylized defined benefits plan. The optimal assetallocation policies consist of the replicating portfolio independentof the pension liabilities. We show that the worker with retirewhen the ratio of pension benefits to current wages reachesa critical value which depends on the parameters of the pensionplan and the discount rate. Using numerical techniques we analyzethe feedback effect of retirement policies on the valuationof plans and on the asset allocation decisions.     

我国炼油工业应实行改造与新建并举的方针

目前我国炼油工业的生产能力，特别是加工中东含硫油的能力严重不足，为适应国民经济发展的需要，扩大炼油能力十分必要，根据测算，2010年我国炼油工业的加工量应达到3亿吨，2020年达到4．5亿吨，若按开工率90％计，则2010年我国炼油能力应达到3．3亿吨，2020年达到5亿吨，因此，从现在开始的10年内，需新增炼油能力1亿吨左右，在下一个10年，即2010至2020年，还需新增能力1．5亿吨，根据我国国情，因地制宜，充分利用现有装置潜力通过技术改造来发展炼油工业是十分必要的，但是大型，先进，一体化是我国炼油工业今后发展的主要方向，兴建新厂可采用先进的工艺技术和新的管理机制，取得较高的经济效益，因此，我国炼油工业的发展实行技术改造与兴建新厂并举的“两条腿走路”的方针。     

The economics of land transfer and title insurance

In the presence of uncertainty over the title of land (due to fraud or error), a legal system can protect either the current (innocent) owner, or a previous owner who claims title. The predominant system in the United States generally awards title to the latter in the event of legitimate claim. Thus, current owners frequently purchase title insurance to provide indemnification in the event of a loss. In contrast, the Torrens system awards title to the current owner, but provides for indemnification of any legitimate claimants. We evaluate these two systems and argue that if transaction costs are low, both promote efficient assignment of title (according to the Coase Theorem), but if transaction costs are high, the Torrens system is more likely to award title to the party that values it the most (namely, the current possessor).     

A conceptual framework of anonymity in Group Support Systems

As the development and use of automated systems for collaborative work grows, the need for a better understanding of these systems becomes more important. Our focus is on one type of system, a Group Support System (GSS) and, in particular, on one important aspect of a GSS—anonymity. A conceptual framework for the study of anonymity in a GSS is presented, which describes the general classes of variables and their relationships. These variables include the factors that influence anonymity in a GSS, types of anonymity, and the effects of anonymity on a message sender, receiver, group process, and outcome. Each of these variables is discussed with working propositions presented for important group process and outcome measures. The objectives of this article are to highlight the importance and complexity of anonymity, to act as a guide for empirical investigations of anonymity, and to influence future GSS development and use.     

基于神经网络的降雨径流预报

本文将人工神经网络应用于二滩水电站以上支流鱼河的降雨径流预报，通过建模、计算、比较和分析可知，其非线性映射能力、自学习能力和灵活性，均能较好地反映降雨径流之间的非线性的、复杂的转换关系，结合流域水文特性并合理处理建模数据，值得进一步深入研究。     

Classification and aggregation: An application to industrial classification in cps data

In this paper we offer a method for deciding how to aggregate a set of elementary industries. The method is then applied to the problem of estimating a wage equation that allows for industry-specific effects. Our method explicitly formalizes the trade-off between goodness-of-fit and parsimony implicit in an aggregation problem. By varying the parameter of the assumed loss function, one obtains a whole sequence of aggregation levels. Further, the resulting sequence is consistent; that is, groupings formed at one level of aggregation will never be undone when one aggregates further.     

Zooplankton population in the river tigris: Effects of samarra impoundment

The influences of the Samarra impoundment on the ecology of the downstream sector of the river Tigris are investigated. Zooplankton were collected monthly from July 1987 to July 1988. It was found that zooplankton were most abundant during high river discharges in March. During the month of low river discharge, September, the zooplankton population was greatly reduced immediately below the barrage and remained so to the last downstream station. Several factors seem to explain such differences. The high discharge from the impoundment was found to be the dominating factor and may flush the small backwaters in which zooplankton were abundant, thus increasing the population in the river. Zooplankton species vary in their ability to sustain populations in the river, variations which are due mainly to species-specific characteristics.     

On the Role of Futures Trading in Spot Market Fluctuations: Perpetrator of Volatility or Victim of Regret?

We examine the role of index futures trading in spot market volatility. We use the exponential generalized autoregressive conditional heteroskedasticity (EGARCH) approach to measure volatility, analyze causality and feedback relations between volatilities in the spot and futures markets, and test various hypotheses in the context of a multivariate model that incorporates other macrostate variables. Our empirical results suggest index futures trading may not be blamed for the observed volatility in the spot market. Rather, we find stronger and more consistent support for the alternative posture that volatility in the futures market is an outgrowth of a turbulent cash market. We use the regret (cognitive dissonance) theory to explain our results.     

The impact of cleaner processing on nutrient availability in the bleached kraft industry.

The pulp and paper industry has invested heavily over recent years in cleaner processing, to reduce losses and minimise its impact on the environment. Over the past fifteen years, a New Zealand integrated bleached kraft mill has undergone a comprehensive programme of upgrades to increase production, reduce water consumption and streamline its biological treatment process. Whilst the overall discharge of contaminants from the site decreased, the treatment system performance did not show a concurrent improvement as may have been expected. Reduced BOD removal, low dissolved oxygen levels, and poor solids settlability were symptomatic of phosphorus limitation in the aerated lagoon treatment system. The wastewater entering the system was found to be phosphorus limited at a BOD:P ratio of 100:0.2. Mono-ammonium-phosphate was supplemented, at approximately 30 kg P/d, to raise the phosphorus levels to a BOD:P ratio of 100:0.3. Treatment efficiencies improved very quickly after phosphorus dosage, with a 50% reduction in BOD and TSS discharge, a significant increase in dissolved oxygen levels, and improved BOD removal (85% to 93%). This case study demonstrates that whilst more closed operation can result in reduced discharge of organic loads, there may be negative impacts on the availability of nutrients for balanced biological growth.