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141.
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Abstracts     
Quality & Quantity -  相似文献   
143.
This article investigates transitions at the level of societal functions (e.g., transport, communication, housing). Societal functions are fulfilled by sociotechnical systems, which consist of a cluster of aligned elements, e.g., artifacts, knowledge, markets, regulation, cultural meaning, infrastructure, maintenance networks and supply networks. Transitions are conceptualised as system innovations, i.e., a change from one sociotechnical system to another. The article describes a co-evolutionary multi-level perspective to understand how system innovations come about through the interplay between technology and society. The article makes a new step as it further refines the multi-level perspective by distinguishing characteristic patterns: (a) two transition routes, (b) fit–stretch pattern, and (c) patterns in breakthrough.  相似文献   
144.
This article examines the effect of the Private Securities LitigationReform Act of 1995 (PSLRA) on stockholder lawsuits. We explorethe role of restatements, earnings forecasts, and insider tradingin the filing and resolution of lawsuits for a sample of hightechnology firms. Consistent with our predictions, there isa post-PSLRA shift away from litigation based on forward-lookingearnings disclosures. Conversely, there is a significantly greatercorrelation between litigation and both earnings restatementsand abnormal insider selling after the PSLRA. Finally, we finda post-PSLRA increase in the likelihood of settlement for casesinvolving earnings restatements.  相似文献   
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This paper uses the method of assumptional analysis to understand the behavior patterns and the problem-solving strategies employed by the engineer/scientist. It is shown that the engineering mindset, although useful for the solution of the problem situations that generally arise in the engineering fields, has serious inadequacies, and is often counterproductive, in handling ill-structured management problems; hence, the often reported, less-than-adequate performance of engineers in management situations. This article moves from the analysis of engineering-problem situations to the basic assumptions underlying the engineer's world picture and thence to the engineer's strategies for problem solution. Comparisons with the nature of management situations, the manager's world picture, and his problem-handling activities are made. The analysis is, in the main part, paradigmatic. It is pointed out that the basic feature of all ill-structured problems is that they network across many and diverse knowledge bases. Further, this article argues that a new and different world view needs to be introduced into the training of future generations of engineers, for with the increased networking of society, not just management but also technological problem situations will move more and more towards the ill-structured end of the spectrum.  相似文献   
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This paper tests the significance and the non-linearity of the Phillips trade-off in the aggregate Euro Area, in an unobserved components model of stochastic NAIRU and trend output featuring the Phillips equation and the Okun law as main identifying equations, with quarterly data for 1970:I-2002:III. The Phillips curve turns out to be linear and its trade-off statistically significant, while non-linearity shows up in the Okun relation. The results prove to be robust to alternative lag length structures of the model, and to alternative non-linear functional forms. The trend-cycle decompositions estimated with the model capture the main features of the Euro Area’s recent macroeconomic record.First version received: 1 September 2003 / Final version received: June 2004CEMPRE - Centro de Estudos Macroeconómicos e Previsão - is supported by the Fundação para a Ciência e a Tecnologia, Portugal, through the Programa Operacional Ciência, Tecnologia e Inovação (POCTI) of the Quadro Comunitário de Apoio III, which is financed by FEDER and Portuguese funds.We thank comments on earlier versions by Fabio Canova, Miguel St Aubyn, Alvaro Almeida, Pete Richardson, Kevin Ross, and two anonymous referees. We acknowledge James D. Hamilton’s help with the confidence bands. The usual disclaimer applies.  相似文献   
149.
Historical data for the manufacturing industry in the United States and United Kingdom are quoted, showing in most cases divergences between Laspeyres and Paasche forms of the quantum index that are by no means negligible. When the Paasche index for two of the series is recalculated with quantity indicators for industries instead of for products, the divergence is greatly reduced, and when quantity indicators for industry groups are substituted it almost disappears. This raises some questions about the practices of econometricians and statisticians, which are discussed. In a mathematical appendix by E. R. Coleman it is suggested that the grouping effect referred to does not depend on the particular way in which the data are grouped in most quantum indexes.  相似文献   
150.
We study a dynamic duopoly model with network externalities. The value of the product depends on the current and past network size. We compare the market outcome to a planner. With equal quality products, the market outcome may result in too little standardization (i.e. too many products active in the long run) but never too much. The potential inefficiency is non-monotonic in the strength of the network effect, being most likely for intermediate levels. When products differ in quality, an inferior product may dominate even when the planner would choose otherwise, but only if the discount factor is sufficiently large  相似文献   
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