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951.
952.
If actively managed mutual funds suffer from diminishing returns to scale, funds should alter investment behavior as assets under management increase. Although asset growth has little effect on the behavior of the typical fund, we find that large funds and small‐cap funds diversify their portfolios in response to growth. Greater diversification, especially for small‐cap funds, is associated with better performance. Fund family growth is related to the introduction of new funds that hold different stocks from their existing siblings. Funds with many siblings diversify less rapidly as they grow, suggesting that the fund family may influence a fund's portfolio strategy. 相似文献
953.
954.
在Bergman空间上讨论了以拟齐次函数为符号的Toeplitz算子的乘积问题.使用Mellin变换作为工具,得出了当拟齐次函数的度都为正度时两个Toeplitz算子乘积仍是Toeplitz算子的充分必要条件,完善了以往文献中的有关结果. 相似文献
955.
Local conservation efforts are often related to benefits at higher governmental levels. On the one hand, these efforts are strongly connected to local land-use decisions. On the other hand, activities such as sustainable water management or biodiversity conservation are associated with regional, national or even global public goods. Therefore, spatial externalities or spillovers exist, which—if not adequately compensated for—lead to an underprovision of the public goods and services concerned. This article investigates intergovernmental fiscal transfers as an innovative instrument for compensating local jurisdictions for the ecological goods and services they provide across local boundaries. From a public finance perspective, fiscal transfers are a suitable instrument for internalising spatial externalities. However, most federal states use this instrument predominantly for social and economic public sector functions rather than for ecological ones. This article investigates the case of the ecological “ICMS” that was first introduced by a few states in Brazil during the 1990s. Part of the revenue from this value-added tax is redistributed to the local level on the basis of ecological indicators. In this way, the state level uses fiscal transfers to compensate municipalities for the existence of protected areas and other ecological services provided within their territories. The Brazilian experience illustrates that such fiscal transfers can represent both a compensation for land-use restrictions and an incentive to value and engage in more conservation activities at the local level. 相似文献
956.
R, an open‐source programming environment for data analysis and graphics, has in only a decade grown to become a de‐facto standard for statistical analysis against which many popular commercial programs may be measured. The use of R for the teaching of econometric methods is appealing. It provides cutting‐edge statistical methods which are, by R's open‐source nature, available immediately. The software is stable, available at no cost, and exists for a number of platforms, including various flavours of Unix and Linux, Windows (9x/NT/2000), and the MacOS. Manuals are also available for download at no cost, and there is extensive on‐line information for the novice user. This review focuses on using R for teaching econometrics. Since R is an extremely powerful environment, this review should also be of interest to researchers. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
957.
This paper examines the effect of memory loss on the continuity of behavior. We consider a player (individual or firm) who remembers previous actions but not underlying rationales. In a stable environment, relative to a full-recall scenario, memory loss increases the probability of following old policies (inertia). In a volatile environment, memory loss can decrease this probability (impulsiveness). The model provides a memory-loss explanation for some documented psychological biases, implies that inertia and organizational routines should be more important in stable environments than in volatile ones, and provides empirical implications relating memory and environmental variables to economic decisions. 相似文献
958.
This paper examines the spatial patterns of unemployment in Chicago between 1980 and 1990. We study unemployment clustering with respect to different social and economic distance metrics that reflect the structure of agents' social networks. Specifically, we use physical distance, travel time, and differences in ethnic and occupational distribution between locations. Our goal is to determine whether our estimates of spatial dependence are consistent with models in which agents' employment status is affected by information exchanged locally within their social networks. We present non‐parametric estimates of correlation across Census tracts as a function of each distance metric as well as pairs of metrics, both for unemployment rate itself and after conditioning on a set of tract characteristics. Our results indicate that there is a strong positive and statistically significant degree of spatial dependence in the distribution of raw unemployment rates, for all our metrics. However, once we condition on a set of covariates, most of the spatial autocorrelation is eliminated, with the exception of physical and occupational distance. Racial and ethnic composition variables are the single most important factor in explaining the observed correlation patterns. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
959.
该文分别从经济效益最大化和生态效益最大化的目标出发,以土地资源、农作物用水量、区域各类农作物需求量和农业生产直接投入为约束条件,基于线性规划方法建立武威市凉州区农业种植业结构优化的经济效益模型和生态效益模型,并对两个模型的优化结果进行对比分析,认为以草地生态农业为生产模式的生态效益模型是凉州区实现农业可持续发展较为理想的模型。 相似文献
960.
财政是新疆农业防灾救灾的主体,防灾救灾机制决定了其效率.本文通过对新疆近年来财政支持防灾救灾机制的现状、问题的研究,提出如何建立适合新疆财政防灾救灾机制的对策建议. 相似文献