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151.
Initial margin requirements represent: (1) a cost impediment to the wealth constrained investor and (2) a potential way of mitigating excessive volatility. However, prior empirical research finds that margins are not an effective tool in reducing volatility. We consider the possibility that margins primarily affect certain stocks and investors. Specifically, we test whether margins affect individuals who, as a group, we believe to be the investors most affected when margin requirements change. Our initial empirical tests, however, do not support this contention.  相似文献   
152.
This paper applies a stochastic frontier production model with time-varying technical efficiency to investigate the relationship between public capital and technical efficiency. It is based on the proposition that public capital has an effect on actual output by enhancing technical efficiency, thereby reducing the gap between maximum potential output and actual output. Empirical results using panel data from U.S. state manufacturing industries during 1969–86 show that technical efficiencies varied substantially, both between states and between years; variations in technical efficiency are significantly explained by variations in public-sector capital.
JEL Classification Numbers: O20, H54, C23.  相似文献   
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This article is a navigation guide to the twenty papers that emerged from the workshops conducted at the Sixth Invitational Choice Symposium (Estes Park, Colorado, June 2004). The papers are categorized into three broad sets that focus respectively on choice modeling issues, on providing interdisciplinary perspectives on choice, and on relating choice research to real world concerns. Within each category, we offer provide brief integrative overviews linking subsets of papers.  相似文献   
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文章论述了环境问题对人类的重要性及创造环保型的企业环境需要解决的问题,在此基础上,提 出了为实现环保型企业经营韩国政府所应该采用的政策及具体的实施方案。  相似文献   
159.
The present contribution analyzes the implications of two central factors influencing the asset allocation decision of (German) life insurance companies, the development of the equity market on one hand and the interest rate guarantees included in traditional life insurance products on the other. The adverse development of share prices in 2000–2002 implies the necessity to consider not only ?normal“ volatility but also worst case-developments for the purpose of risk control. Formally this is done by using the risk measures value-at-risk and conditional value-at-risk. The specific ?myopic“ nature of interest rate guarantees in German life insurance products, which are granted on a yearly basis implies — beyond the general control of the shortfall risk with respect to the guaranteed interest rates — the necessity to per-form the asset allocation on a yearly basis to be in conformity with the time horizon of the liabilities.On the basis of a quantitative approach corresponding model calculations are performed. Thereby not only a pure market valuation is considered but also institutional peculiarities (hidden reserves, accounting norms) of German life insurance companies. The possibility of a riskless one-year investment, either based on market values or on balance sheet values, is revealed to be crucial for giving interest rate guarantees on a yearly basis.  相似文献   
160.
A feature transformation method based on domain knowledge for arti?cial neural networks (ANNs) is proposed. The method of feature transformation based on domain knowledge converts continuous values into discrete values in accordance with the knowledge of experts in speci?c application domains. This approach effectively ?lters data, trains the classi?er, and extracts the rules from the classi?er. In addition, it reduces the dimensionality of the feature space, which not only decreases the cost and time in the operation but also enhances the generalizability of the classi?er. The experimental results of the proposed approach will be compared and tested statistically with the results of the linear transformation method. The results show that the method of feature transformation based on domain knowledge outperforms the linear transformation in modelling of ANNs. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
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