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991.
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   
992.
武威市凉州区农业种植结构调整的双目标优化   总被引:7,自引:0,他引:7       下载免费PDF全文
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   
993.
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   
994.
995.
江苏省高级技能人才供需缺口原因与解决对策研究   总被引:1,自引:0,他引:1  
随着江苏省经济的快速发展,高级技能人才供不应求的矛盾日益凸现.文章通过实地调研的方法,深入分析了其内在原因,在此基础上,有的放矢地提出企业、政府乃至全社会需要努力的方向,以期从根本上解决江苏省目前的高级技能人才供需缺口问题.  相似文献   
996.
The hypothesis that a stock market price index follows a random walk is tested for 11 African stock markets, Botswana, Côte d'Ivoire, Egypt, Ghana, Kenya, Mauritius, Morocco, Nigeria, South Africa, Tunisia and Zimbabwe using joint variance ratio tests with finite-sample critical values, over the period beginning in January 2000 and ending in September 2006. The iid random walk hypothesis is rejected in all 11 markets. In four stock markets, Egypt, Nigeria, Tunisia and South Africa, weekly returns are a martingale difference sequence. Liquidity is an important factor which contributes to whether a stock market follows a random walk.  相似文献   
997.
998.
This article investigates the determinants of real estate investment trusts (REIT) portfolio investment and institutional REIT ownership using multivariate Tobit regressions. We contend that many institutional investors take larger positions in more liquid assets like REIT stocks, as compared with private real estate equities, because of liquidity considerations. Consistent with this contention, we find that liquidity constraints are significantly related to REIT portfolio investment by institutional investors. We also find that institutional investors have different preferences for REIT stocks than do other investors; they generally prefer larger, more liquid REIT stocks.  相似文献   
999.
Where the quality (both competence and independence) of an audit is tested, often in the circumstance of a corporate failure, auditors frequently have good defences as to their competency but rarely do they have equally convincing defences for the objectivity of their decisionmaking or the independence of their audit. This paper recommends that large audit firms establish an independence board with the authority to define, review and decide upon all threats and potential threats to independence. It would also have responsibility for quality-control and educational programs in respect of audit firm's independence decision-making.  相似文献   
1000.
We study all–pay auctions with variable rewards under incomplete information. In standard models, a reward depends on a bidder's privately known type; however, in our model it is also a function of his bid. We show that in such models there is a potential for paradoxical behavior where a reduction in the rewards or an increase in costs may increase the expected sum of bids or alternatively the expected highest bid.  相似文献   
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