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771.
Tracking programs have been criticized on the grounds that they harm disadvantaged children. The bulk of empirical research supports this view, but existing studies compare outcomes across students placed in different tracks. Track placement is likely to be endogenous with respect to student outcomes. We use a new strategy for overcoming the endogeneity of track placement and find no evidence that tracking hurts low-ability children. Previous studies have also been based on the assumption that students' enrollment decisions are unrelated to whether or not the school tracks. When we account for the possibility that tracking programs affect school choice, we find evidence that they may help low-ability children. 相似文献
772.
The assessment of public universities has gained importance because of the demands from such state government bodies as the executive and the legislature. Public universities are increasingly being asked to account for how efficiently they have used diminishing state financial resources. Administrators thus have the responsibility of ensuring that the university's financial, human, and physical resources are allocated to academic departments in a manner that enhances the institution's efficiency. In this paper, data envelopment analysis (DEA) is proposed for evaluating the efficiency of academic departments at a public university. DEA provides a single measure of efficiency for each academic unit. It also identifies the causes behind the inefficiencies exhibited by poor performing units, as well as the changes that these units need to make in order to improve their efficiencies. Its usefulness as a planning tool is also discussed. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Muzaffer S. 《Annals of Tourism Research》2002,29(4)
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This paper investigates whether governments can change market structures through interventions. We study the effects of four political events over the life cycle of the market for daily newspapers in the Netherlands. We find that policy measures meant to lower entry barriers in an expanding industry created new entry and increased survival chances for potential entrants and incumbent newspapers. Exit barrier enhancing policies to reduce concentration tendencies have not been successful. 相似文献
780.
Denial of Service (DoS) attacks consist of overwhelming a server, a network or a Web site in order to paralyze its normal activity. The additional parameter in Distributed Denial of Service (DdoS) attacks is the distributing strategy. It means that DDoS attacks do not come from a single computer but stem from all accessible channels and servers. Consequences are multiple, ranging from system errors, temporary inability to access the Web site for normal users to challenging the actual reliability of the Internet. Despite this, Internet users show carelessness. The explanation lies in the specificities of DDoS attacks. We explore possibilities to raise users' awareness about the actual amplitude of problems caused by DDoS attacks. We suggest a careful examination of Internet pricing mechanisms and switching from flat to usage-constraining pricing schemes. 相似文献