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1.
In global markets, the market shares of the two or three biggest firms sum up more than 90 percent and firms do marketing efforts. However, the classical neo-walrasiano theoretical framework only is able to justify these stylized facts with particular firms’ cost structures, being one reason the presumption that there are no information costs. Towards the rationalization of those stylized facts, I study the evolution of the market structure in a model of price advertising with a variable that controls the degree of openness of regional markets. The main result of the model is that in equilibrium the structure of a global market is the duopoly.  相似文献   
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We develop a structural risk‐neutral model for energy market modifying along several directions the approach introduced in Aïd et al. In particular, a scarcity function is introduced to allow important deviations of the spot price from the marginal fuel price, producing price spikes. We focus on pricing and hedging electricity derivatives. The hedging instruments are forward contracts on fuels and electricity. The presence of production capacities and electricity demand makes such a market incomplete. We follow a local risk minimization approach to price and hedge energy derivatives. Despite the richness of information included in the spot model, we obtain closed‐form formulae for futures prices and semiexplicit formulae for spread options and European options on electricity forward contracts. An analysis of the electricity price risk premium is provided showing the contribution of demand and capacity to the futures prices. We show that when far from delivery, electricity futures behave like a basket of futures on fuels.  相似文献   
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While the biofouler Corbicula fluminea (Müller, 1774) is known to cause great economic losses in North America, studies reporting the problem in Europe are much scarcer. This paper explores the industrial effects of the species in Portugal, the gateway by which the bivalve entered Europe around 30 years ago. National waterworks, major power stations, cement plants, pulp and paper mills and irrigation systems were surveyed. The industrial impacts of the pest were shown to remain relatively mild; irrigation systems are those that seem to be facing more significant economic losses due to infestation. Possible reasons for the apparent discrepancy between this result and the species dispersal in natural ecosystems are discussed, and recommendations on adequate responses to the latent threat are provided. This study may assist the implementation of integrated pest management policies in countries at risk of invasion or recently invaded, and contribute to an understanding of the species’ progression in industrial environments.  相似文献   
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The Brazilian cities as well as many of the large urban centers in the world continue to expand, increasing the demand for mobility and transport, while, at the same time, the same cities are investing in greenhouse gas (GHG) mitigation to avoid climate change. Brazil's urbanization rate increased from 26% in 1940 to almost 70% in 1980. During this period, the Brazilian population tripled and the urban population multiplied by seven. In 2010, the transport sector in São Paulo accounted for 71% of the total emissions released by the energy sector. Ethanol has been considered a fuel with less greenhouse gas emissions, when compared with fossil fuels. However, ethanol production would have to double to meet the expected demand. Electric vehicles (EVs) market is expanding around the world, and is also an option to reduce the transport emissions, if powered by clean electricity. To assess whether the adoption of EVs might bring more benefits than the current ethanol, we develop prospective scenarios supported by the Long-range Energy Alternatives Planning (LEAP) simulation tool, taking a bottom-up tank-to-wheel approach to consider the CO2 emissions of car in São Paulo. The scenario considering a substitution of 25% of gasoline-powered cars by EV in 2030 showed a reduction in energy consumption and CO2 emissions, around 15% and 26% respectively in that year in comparison with 2015. We discuss the interplay between ethanol and EV, also considering emission coefficients from life cycle analysis conducted in Brazil, and concluded EV will have higher positive impact on climate change mitigation than ethanol.  相似文献   
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In this article, we report on the findings of an exploratory, interpretive study of a notorious corporate fraud that occurred in Brazil from 1989 to 2005. We examine the process by which this scheme was created as well as how it was maintained for all those years. Our analysis covers both the substantive aspects (the actions fraud agents effectively perform) and the symbolic aspects (the resources of impression management that they use). We suggest that under certain circumstances, corporate frauds may be understood as the result of implementation of a criminal business model that focuses on a niche market of risk takers or greed investors, uses aggressive commercial practices and offers exclusivity, promotes the organization's image and personality cult of the entrepreneur, operates a management model that combines centralized control with fragmented systems, and uses complex fraudulent practices. This perspective allows us to understand the phenomenon of corporate fraud from a systemic point of view. We also suggest directions for future research and theory development on corporate frauds. © 2014 Wiley Periodicals, Inc.  相似文献   
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This paper presents a compilation and empirical survey‐based evaluation of the metrics most commonly used by program managers during product development management. This work is part of a bigger project of Massachusetts Institute of Technology (MIT), Project Management Institute (PMI) and International Council on Systems Engineering (INCOSE). Three methodological procedures were applied: systematic literature review, focus‐group discussions, and survey. The survey results indicate the metrics considered to be the most and least useful for managing lean engineering programs, and reveals a shift of interest towards qualitative metrics, especially the ones that address the achievement of stakeholder values, and the absence of useful metrics regarding the lean principles People and Pull.  相似文献   
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Editors’ note     
Portuguese Economic Journal -  相似文献   
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