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1.
Bio-economic modelling has become a useful tool for anticipating the outcomes of policies and technologies before their implementation. Advances in mathematical programming have made it possible to build more comprehensive models. In an overview of recent studies about bio-economic models applied to land-use problems in agriculture and forestry, we evaluated how aspects such as uncertainty, multiple objective functions, system dynamics and time have been incorporated into models. We found that single objective models were more frequently applied at the farm level, while multiple objective modelling has been applied to meet concerns at the landscape level. Among the objectives, social aspects are seldom represented in all models, when being compared to economic and environmental aspects. The integration of uncertainty is occasionally a topic, while stochastic approaches are more frequently applied than non-stochastic robust methods. Most multiple-objective models do not integrate uncertainty or sequential decision making. Static approaches continue to be more recurrent than truly dynamic models. Even though integrating multiple aspects may enhance our understanding of a system; it involves a tradeoff between complexity and robustness of the results obtained. Land-use models have to address this balance between complexity and robustness in order to evolve towards robust multiple-objective spatial optimization as a prerequisite to achieve sustainability goals.  相似文献   
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We comprehensively analyze the predictive power of several option-implied variables for monthly S&P 500 excess returns and realized variance. The correlation risk premium (CRP) and the variance risk premium (VRP) emerge as strong predictors of both excess returns and realized variance. This is true both in- and out-of-sample. Our results also reveal that statistical evidence of predictability does not necessarily lead to economic gains. However, a timing strategy based on the CRP leads to utility gains of more than 5.03% per annum. Forecast combinations provide stable forecasts for both excess returns and realized variance, and add economic value.  相似文献   
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This paper contributes to the understanding of the long-run consequences of Roman rule on economic development. In ancient times, the area of contemporary Germany was divided into a Roman and a non-Roman part. The study uses this division to test whether the formerly Roman part of Germany are more developed than the non-Roman part. This is done using the Limes Germanicus wall as geographical discontinuity in a regression discontinuity design framework. The results indicate that economic development—as measured by luminosity—is indeed significantly and robustly larger in the formerly Roman part of Germany. The study identifies the persistence of the Roman road network until the present as an important factor causing this developmental advantage of the formerly Roman part of Germany both by fostering city growth and by allowing for a denser road network.  相似文献   
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Regarding formal, linguistic and content-related characteristics, tabloid newspapers have a relatively high potential to emotionally arouse readers, whereas broadsheets present news in a more factual style. In the present study it is argued that the usage of the different types of newspapers affects attitude structures. Specifically, it is assumed that the frequency of usage and expected gratifications during usage have an effect on the affective-cognitive attitude basis. Results of a survey (N = 505) support the hypotheses on the emotion gap: Heavy users of broadsheets base their attitudes on cognitions, regardless of their expected gratifications. For heavy users of tabloid newspapers, expected gratifications moderate the effect of usage on attitude bases: Information-oriented tabloid recipients hold cognition-based attitudes; entertainment-oriented tabloid recipients hold affect-based attitudes.  相似文献   
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Start-ups face branding challenges. Not only are they confronted with the task of building brands from scratch, their newness also leads to a particularly high amount of customer uncertainty. This paper contributes to the emerging field of entrepreneurial branding by investigating start-up characteristics that signal trustworthy information to potential customers. An extended choice-based conjoint approach for modeling brand equity is used to explore the impact of different signals as initiated by established and new firms in the field of tablet computers. An empirical study reveals brand signals that have significant effects on purchase probabilities and are appropriate to overcome information asymmetries between start-ups and prospective customers.  相似文献   
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Ensemble methods can be used to construct a forecast distribution from a collection of point forecasts. They are used extensively in meteorology, but have received little direct attention in economics. In a real-time analysis of the ECB’s Survey of Professional Forecasters, we compare ensemble methods to histogram-based forecast distributions of GDP growth and inflation in the Euro Area. We find that ensembles perform very similarly to histograms, while being simpler to handle in practice. Given the wide availability of surveys that collect point forecasts but not histograms, these results suggest that ensembles deserve further investigation in economics.  相似文献   
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The evolution of private labels (PLs) can be understood in terms of a strategy adopted by the retail industry with the aim of competing with national brands (NBs). In the 1990s, this strategy led to the development of ‘me too’ products, which currently represent the largest share of store brand products. Since the early 2000s, retailers have widened the range of their store brands by introducing high‐quality products. The aim of this study was to estimate consumers’ attachment to ‘me‐too’ and niche PLs respectively, as compared to NBs. We captured the degree of maturity of these PLs through their price‐elasticities, computed for three staple goods offered by three mass retail companies. It was found that price sensitivity does not differ much between the ‘me‐too’ PLs and the corresponding NBs. This result confirms that ‘me‐too’ products are now considered reliable quality brands. However, in the high quality segment, consumers remain more sensitive to the price of PLs than to that of NBs, a characteristic which may relate to their recent introduction on the market.  相似文献   
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We extend the fundamental theorem of asset pricing to the case of markets with liquidity risk. Our results generalize, when the probability space is finite, those obtained by Kabanov et al. [Kabanov, Y., Stricker, C., 2001. The Harrison-Pliska arbitrage pricing theorem under transaction costs. Journal of Mathematical Economics 35, 185–196; Kabanov, Y., Rásonyi, M., Stricker, C., 2002. No-arbitrage criteria for financial markets with efficient friction. Finance and Stochastics 6, 371–382; Kabanov, Y., Rásonyi, M., Stricker, C., 2003. On the closedness of sums of convex cones in L0L0 and the robust no-arbitrage property. Finance and Stochastics] and by Schachermayer [Schachermayer, W., 2004. The fundamental theorem of asset pricing under poportional transaction costs in finite discrete time. Mathematical Finance 14 (1), 19–48] for markets with proportional transaction costs. More precisely, we restate the notions of consistent and strictly consistent price systems and prove their equivalence to corresponding no arbitrage conditions. We express these results in an analytical form in terms of the subdifferential of the so-called liquidation function. We conclude the paper with a hedging theorem.  相似文献   
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