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从消费者效用角度研究了一个网络音乐厂商与一个传统音乐厂商构成的双寡头垄断市场中的产品定价策略,构建Hotelling博弈模型,探讨了网络外部性对音乐厂商最优定价、利润变化趋势和市场盗版水平的影响。研究发现:有网络外部性时,不论网络音乐厂商还是传统音乐厂商,产品价格都上升;网络音乐厂商的利润必然上升,而传统音乐厂商的利润可能下降。网络外部性的存在增大了整个音乐市场的需求,盗版的需求也随之增大,但市场竞争加剧导致盗版市场份额可能下降。 相似文献
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文章运用动态博弈的方法研究了在网络外部性特征显著的本国市场中,当政府对进口企业征收从量关税时,提供具有纵向差异产品的国外企业和国内企业的价格竞争和兼容策略问题。结论表明,网络外部性加剧了国内外企业间的价格竞争,但相互兼容可以弱化竞争激烈程度,因此二者都偏好兼容;关税对质量差异具有强烈的替代效应,适当的关税水平既有利于本国企业成长又有利于国外企业的市场进入;边际兼容成本的大小决定了国内外企业的最优兼容水平的高低,即决定了谁具有更强的兼容动机。文章结论在一定程度上为相关企业的兼容性决策和政府的关税调控提供了理论支持。 相似文献
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考虑了两家企业1和2,其中仅企业1雇用企业管理者管理企业,企业2的所有者就是企业管理者。运用博弈论研究网络外部效应下企业管理者的激励问题。研究表明,当网络外部性满足一定的条件时,随着产品间相关性的变化,激励参数的改变对企业1和企业2的产量和价格决策将造成不同的影响。网络外部效应、产品间的相关性以及单位成本的改变将影响最优激励参数。其中,网络外部效应越大,则最优激励参数越小。网络外部性总是提高均衡产量和利润,而均衡价格可能提高、减少或保持不变。网络外部性还将进一步加大由于企业管理者决策目标不相同所带来的企业之间的均衡产量、价格和利润差距。 相似文献
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网络企业纵向并购的模型分析 总被引：3，自引：0，他引：3
本文主要以美国在线怀时代华纳的兼并案为例子，考虑双寡头垄断的上游企业和双寡头垄断的下游企业市场上发生的纵向兼并行为。这里考虑网络企业的一个主要特征是他们的产品具有网络外部性，然后对兼并前和兼并后企业的利润、产品的价格及网络外部性对兼并行为发生的影响进行了比较分析并得出相应的结论。本文的对於对目前国内网络企业的并购行为具有理论指导作用。 相似文献
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技术差距是影响企业产品创新的重要因素。在市场未完全覆盖条件下,构建了纵向差异化的两阶段双寡头博弈模型,分析技术差距对竞争均衡时企业的利润、市场份额、消费者剩余和社会福利的影响;并考察在不同竞争类型下企业的策略选择和政府制定政策的差异。研究表明:高(低)质量企业为提高利润水平有加大研发投入从而扩大(缩小)技术差距的激励;政府出于对社会福利的考虑,在Bertrand竞争时倾向于限制技术差距,而在Cournot竞争时则鼓励技术差距的存在。 相似文献
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基于下游产品存在纵向差异,研究了上下游厂商的价格决策问题,主要包括三种渠道权力对下游产品质量和产量、上下游产品价格、消费者剩余和社会福利的影响。研究表明：（1）上游厂商实行了价格歧视,对下游高质量厂商的批发价格大于对下游低质量厂商的批发价格。（2）无论上下游厂商哪一方处于领导地位,都会导致下游厂商提高产品质量和价格,降低产品产量。（3）对上游厂商而言,处于领导地位时利润最高,处于跟随地位时利润最低。对下游厂商也有类似的结论。此外,三种权力结构下都存在高质量优势。（4）无论消费者购买哪种质量的产品,在纵向纳什权力结构下剩余最多,在另两种权力结构下剩余相等。（5）纵向纳什权力结构下社会福利最大,另两种权力结构下社会福利相等。 相似文献
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平台竞争环境下软件产业的纵向一体化选择 总被引：1，自引：0，他引：1
根据软件产业三角式市场结构特点,结合双边市场一般性模型,提出了软件产业平台竞争基本模型,进而分析软件平台竞争的价格结构和利润问题,指出应用软件开发商对用户的组间网络外部性的大小是影响平台及开发商利润的关键因素。通过对比纵向一体化情形下利润及福利水平,得出太强或太弱的组间网络外部性以及较低的整合成本都会使平台产生纵向一体化的激励,纵向一体化行为会导致用户福利降低。 相似文献
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我国B2C与C2C电子商务平台市场近年来发展迅猛.具有纵向差异的综合电子商务平台在潜在竞争压力下会趋于分化.双寡占模型中提供高质量产品的潜在进入者将较之提供低质量产品的在位者获取更高的市场份额与利润.低质量产品供应平台商倾向于选择平台分化.平台分化导致垄断模型中平台间竞争趋于内部化,从而削弱了不同子平台间均衡价格差异.具有纵向差异的子平台间存在交叉平台效应,该效应影响平台提供商的均衡价格与利润.在子平台后向兼容假设下,交叉平台效应将提高提供高质量产品的子平台的价格与利润,提高市场集中度. 相似文献
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摘要：零售商合谋是零售商为提高利润水平而普遍采用的市场手段,它会对渠道价格决策行为产生影响。针对多个制造商和多个零售商组成的常规渠道结构,本文探讨了三种渠道权利结构下零售商合谋对渠道价格决策的影响。研究表明：无论在何种渠道权利结构下,渠道价格决策不受零售商差异化程度的影响;当产品成本大于临界值时,零售商合谋下的批发价格、零售价格高于零售商之间不存在合谋下的相应价格;零售商合谋会使零售商受益,而制造商会受到损害。当产品成本大于临界值时,任何一方在渠道中处于Stackelberg领导者的地位,均会使消费者的福利增加。在 权利结构下,制造商利润水平和零售商利润水平都是最高的。无论在何种渠道权利结构下,如果零售商之间存在合谋,产品差异化程度越大,对制造商越有利,而对零售商有负面效应。 相似文献
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A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
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Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
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《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
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《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
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Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
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Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献