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Opponents of the voluntary labelling scheme for genetically modified (GM) food products often argue that consumers have the “right to know” and therefore advocate mandatory labelling. In this article, we argue against this line of reasoning. Using experimental auctions we show that the quality of the signal generated by a mandatory labelling scheme is affected by the number of labels in the market. If there are two labels, one for GM products and one for non‐GM products, mandatory and voluntary labelling schemes generate a similar degree of uncertainty about the quality of products that do not carry a label.  相似文献   
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In this paper we discuss collaboration in the area of technology management. We propose the concept of collaboration profile to describe various forms of networks along key differentiating characteristics. The collaboration profile is then applied using two examples to illustrate different forms of collaboration in the biotechnology industries, the ‘virtual company’ and the ‘industrial platform’. Based on interviews with members of a virtual company as well as members of industrial platforms and drawing conclusions from theoretical insights, the advantages and disadvantages of these forms and their suitability for different stages of the technology life cycle will be discussed. Specifically, we address the following questions: What kind of collaboration profile applies to virtual companies and industrial platforms? How does the suitability of collaboration forms vary with the stage of technology development? Furthermore, we demonstrate the usefulness of the collaboration profile for analysing features and potential problems of collaborations by describing two examples. Focusing on the key characteristics of a collaboration helps to check the appropriateness of the collaboration form and to identify and manage respective problems.  相似文献   
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ABSTRACT

The precise measurement of the association between asset returns is important for financial investors and risk managers. In this paper, we focus on a recent class of association models: Dynamic Conditional Score (DCS) copula models. Our contributions are the following: (i) We compare the statistical performance of several DCS copulas for several portfolios. We study the Clayton, rotated Clayton, Frank, Gaussian, Gumbel, rotated Gumbel, Plackett and Student's t copulas. We find that the DCS model with the Student's t copula is the most parsimonious model. (ii) We demonstrate that the copula score function discounts extreme observations. (iii) We jointly estimate the marginal distributions and the copula, by using the Maximum Likelihood method. We use DCS models for mean, volatility and association of asset returns. (iv) We estimate robust DCS copula models, for which the probability of a zero return observation is not necessarily zero. (v) We compare different patterns of association in different regions of the distribution for different DCS copulas, by using density contour plots and Monte Carlo (MC) experiments. (vi) We undertake a portfolio performance study with the estimation and backtesting of MC Value-at-Risk for the DCS model with the Student's t copula.  相似文献   
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Zusammenfassung  Job-Food — Das kennt jeder, der in einem Pflegeberuf arbeitet: St?ndige Hektik, der Terminkalender platzt aus allen N?hten, der Schichtwechsel naht und dann f?llt auch noch ein Kollege aus – da bleibt einfach keine Zeit zum Essen. Doch das muss nicht sein.  相似文献   
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In Belgium, several cities have been experimenting with ‘free’ public transport based on the concept of a third payer system. This study explores the modal shift potential of this measure for commuters by means of a large-scale survey. The results indicate that there is still a margin for a further modal shift, but in order to make public transport more attractive to car users, the price paid by the commuter should be lowered, the quality and capacity of the public services should be improved and the mobility policy of the companies should be adjusted in favour of public transport.  相似文献   
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