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41.
Summary. A model that includes the cost of producing money is presented and the nature of the inefficient equilibria in the model are examined. It is suggested that if one acknowledges that transactions are a form of production, which requires the consumption of resources, then the concept of Pareto optimality is inappropriate for assessing efficiency. Instead it becomes necessary to provide an appropriate comparative analysis of alternative transactions mechanisms in the appropriate context. Received: September 5, 2000; revised version: May 3, 2001  相似文献   
42.
This paper analyzes the effects of buyer search costs and seller private and common knowledge on seller competition. It shows that lack of common knowledge results in the equilibrium price continuously decreasing to the perfectly competitive one as buyer search costs for price decrease from positive for all buyers to zero for all buyers, even if each market agent's uncertainty (in the private knowledge) is small. At the same time, if the uncertainty of each seller about buyer valuations is small, the effects of a small change in the search costs or of information structure on pricing may be large (but continuous).  相似文献   
43.
Comprehensive transportation evaluation objects using multi-objective decision method is a process of choosing the best one from a few objects through calculating, analyzing, and comparing the index system. The result may be different because of the difference of the index weight and index value. Therefore, sensitivity analysis should be one of the necessary parts of the decision-making. It is desired to give the index with higher sensitivity and its varying scope to control the index strictly during the execution process. This paper derives transfer index weight, which changes the rank evaluation order of the projects. Meanwhile, a simple, effective and practical method based on sensitivity district and sensitivity matrix is proposed for the sensitivity analysis of decision-making. As an example, the index sensitivity in decision-making of some provinces comprehensive transportation objects, and their influence on the final decision are discussed.  相似文献   
44.
Air transportation is a key strategic asset in that it provides access to markets and thereby enables the economic development of nations. Thus, in order to maintain their competitiveness in a global economy, countries must invest in air transportation infrastructure to ensure their ability to meet current and future demand for aviation services. The objective of this paper is to develop and illustrate a methodology for evaluating the strategic value of air transportation infrastructure, in particular the benefits associated with the ability to react quickly to changes in the market. The hypothesis is that by recognizing and taking advantage of this strategic value, it may be possible to design better policies for aviation infrastructure delivery.The methodology developed here uses system dynamics to model different strategies for infrastructure delivery. These strategies are defined by three variables: the amount of capacity increase, the time to deliver the capacity and the congestion threshold that triggers the need for capacity delivery. Monte Carlo simulation is used to take into account multiple sources of uncertainty. The model shows that a strategy of capacity delivery based on small increments and short response times can yield more benefits than strategies that consider large capacity increases and long response times. Furthermore, in the specific airport example considered here, it was found that a congestion threshold of 75% should be the trigger for capacity enlargements if strategies based on small capacity increments and 1 or 5 years to increase capacity are considered. The lesson for decision-makers is that congestion delays must be addressed with foresight.  相似文献   
45.
Transport development and the evolution of economic geography   总被引:4,自引:0,他引:4  
In this paper, based on the recent advances in the new economic geography (e.g., Fujita et al. [12]), we analyze impacts of transport costs on the spatial patterns of economic agglomeration. We first identify prototypes from the existing models, and explain the mechanism of how transport costs influence the balance between economic forces of agglomeration and dispersion. We then investigate the transformation of the agglomeration/dispersion patterns given gradually decreasing transport costs for different goods.Received: Received: July 2004 / Accepted: January 2005, Accepted: Received: July 2004 / Accepted: January 2005, JEL Classification: R12Tomoya Mori: Correspondence toThe authors are grateful to David Bernstein, Tatsuo Hatta, Komei Sasaki, Tony E. Smith, and two anonymous referees for their valuable comments. This research is partly supported by The Grant in Aid for Research 08403001 of Ministry of Education, Science and Culture in Japan, the Murata Science Foundation, and WESCO Civil Engineering Technology Foundation.  相似文献   
46.
Synopsis This paper is the product of a collaboration between a biologist (Ghiselin 1997) who works on the philosophy of classification and an economist (Landa 1981, 1994) who works on the ‘Economics of Identity’: how and why people classify people based on identity in the context of a theory of ethnic trading networks. In developing the ‘bioeconomics’ (the synthesis of economics with biology) of classification, we crossed a number of disciplinary boundaries—anthropology, economics, sociology, biology, and cognitive psychology including evolutionary psychology’s ‘fast and frugal’ heuristics. Using a bioeconomics approach, we argue that folk classifications—the classifications used by ordinary persons—have much in common with scientific classifications: underlying both is the need for economy of information processing in the brain, for the efficient organization of knowledge, and for efficiency of information acquisition and transmission of information to others. Both evolve as a result of trial and error, but in science there is relatively more foresight, understanding, and planning.  相似文献   
47.
Abstract

Background and aims: A wide range of treatment options are available for hepatocellular carcinoma (HCC), including systemic treatment with tyrosine kinase inhibitors (TKIs) such as sorafenib and lenvatinib, immunotherapies, locoregional therapies such as selective internal radiation therapy (SIRT) and treatments with curative intent such as resection, radiofrequency ablation and liver transplantation. Given the substantial economic burden associated with HCC treatment, the aim of the present analysis was to establish the cost of using SIRT with SIR-Spheres yttrium-90 (Y-90) resin microspheres versus TKIs from healthcare payer perspectives in France, Italy, Spain and the United Kingdom (UK).

Methods: A cost model was developed to capture the costs of initial systemic treatment with sorafenib (95%) or lenvatinib (5%) versus SIRT in patients with HCC in Barcelona Clinic Liver Cancer (BCLC) stages B and C. A nested Markov model was utilized to model transitions between progression-free survival (PFS), progression and death, in addition to transitions between subsequent treatment lines. Cost and resource use data were identified from published sources in each of the four countries.

Results: Relative to TKIs, SIRT with SIR-Spheres Y-90 resin microspheres were found to be cost saving in all four country settings, with the additional costs of the microspheres and the SIRT procedure being more than offset by reductions in drug and drug administration costs, and treatment of adverse events. Across the four country settings, total cost savings with SIR-Spheres Y-90 resin microspheres fell within the range 5.4–24.9% and SIRT resulted in more patients ultimately receiving treatments with curative intent (4.6 vs. 1.4% of eligible patients).

Conclusion: SIR-Spheres Y-90 resin microspheres resulted in cost savings relative to TKIs in the treatment of unresectable HCC in all four country settings, while increasing the proportion of patients who become eligible for treatments with curative intent.  相似文献   
48.
李芬  靳艳魁 《物流科技》2006,29(12):32-34
在中国环境危机和能源危机日益严重的背景下,物流业面临严峻的挑战.因此物流绿色化已成为物流管理系统的发展趋势。本文将从物流过程中的运输环节入手,通过分析传统运输的弊端,探索新型的运输方式,以提高物流绿色化水平。  相似文献   
49.
郝春艳  杨超 《物流技术》2006,(1):48-50,57
在给定一个单源单汇物流运输网络中,网络中的每条弧都有一个容量和运输时间的限制,研究了当网络的容量提高到指定水平,同时限制从网络中源点到汇点运输时间,应该如何对网络进行适当的扩张,减少网络的运输时间,同时使网络效益与预期效益尽可能的接近。  相似文献   
50.
耿雪霏 《物流科技》2005,28(2):51-52
分析我国铁路运输向现代物流发展的必要性及其所具备的优势,并针对目前铁路运输存在的问题.提出其向现代物流发展的对策和建议,  相似文献   
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