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11.
We study the exploitation of a common groundwater resource, first as a static and then as a differential game, in order to take into account the strategic and dynamic interactions among the users of the resource. We suppose that firms can form coalitions or can decide not to cooperate. The non-cooperation regime is characterized by pumping that lead to depletion of the aquifer; the cooperation preserves the resource. Open-loop and feedback equilibria have been computed and compared in order to characterize the existence of cooperators and defectors in water resources management.  相似文献   
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Without guaranteed compensation, granted by the German Renewable Energy Sources Act (Erneuerbare Energien Gesetz/EEG), biogas plants compete with all other plant types on the market for electrical energy. However, exchange-based electricity products do not currently permit an economically viable operation of biogas plants owing to their cost situation.  相似文献   
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Making as a design-centered learning activity has recently received significant attention in education. We use literacies—how individuals use representations to learn—to explore the STEM literacy practices of experienced designers and makers. Describing makers’ representational practices in STEM contexts can inform the design of literacy supports for young makers that can encourage their use of representations to connect STEM disciplines and design practices. We interviewed experienced makers to describe one literacy practice central to design: identifying, organizing, and integrating information. Makers enacted this practice within specific making processes—e.g., designing—with the purpose of sourcing and navigating information related to their chosen problems. The research supports efforts to bridge learning while making with learning in schools by positioning STEM literacies as central practices involved in the processes of designing and making.  相似文献   
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Objective: This study was to determine if calcium fortification yields a higher price per serving in grocery store products. Researchers compared store brand to national brand grocery products in relation to cost in order to examine if calcium values were similar between store brand and national brand products. Methods: A total of 112 store brand and 211 national brand grocery products were collected from three low (national chain store), middle and high priced (Virginia and North Carolina regional store) grocery venues. Products were compared using price and calcium percentage per serving. ANOVA was used to determine between store brand and national brand for price per serving and calcium content, and between grocery venues. Results: National brand fortified products had a significantly lower mean price per serving when compared to national brand non-fortified products (p = 0.0002). There was no statistical difference between store brand fortified and non-fortified products (p = 0.9256). Low priced store brand products had the lowest mean price per serving ($0.34 ±0.24). Conclusions: This study found store brand products have similar calcium content as national brand products. Product cost was lower at low priced store compared to middle and high priced stores.  相似文献   
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Do local partners' network attributes affect the survival of high-tech international joint ventures (IJV)? How does the effect of network attributes vary in different subnational institutional environments? While the classic economic explanation for IJV formation and subsequent performance draws from the resource-based view (RBV), we add the relational dimension to explain that IJV survival may be affected by local partners’ relation-specific assets within the local network. We test the effect of the local partners’ network attributes as calculated by UCINET (centrality, network status, and structural hole position) on IJV survival. We additionally assert that this relationship is moderated by subnational institutional heterogeneity. Using our sample of 125 IJV dyadic pairs of US multinational enterprises (MNEs) operating in high-tech industries and their local partners in China, we find partial support for our claims.  相似文献   
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Kremer and Snyder (Q J Econ 130:1167–1239, 2015) show that demand curves for a preventive and treatment may have different shapes though they target the same disease, biasing the pharmaceutical manufacturer toward developing the lucrative rather than the socially desirable product. This paper tightens the theoretical bounds on the potential deadweight loss from such biases. Using a calibration of the global demand for HIV pharmaceuticals, we demonstrate the dramatically sharper analysis achievable with the new bounds, allowing us to pinpoint potential deadweight loss at 62% of the global gain from curing HIV. We use the calibration to perform policy counterfactuals, assessing welfare effects of government policies such as a subsidy, reference pricing, and price-discrimination ban. The fit of our calibration is good: we find that a hypothetical drug monopolist would price an HIV drug so high that only 4% of the infected population worldwide would purchase, matching actual drug prices and quantities in the early 2000s before subsidies in low-income countries ramped up.  相似文献   
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We explore the innovation performance benefits of alliances for spin-off firms, in particular spin-offs either from other firms or from public research organizations. During the early years of the emerging combinatorial chemistry industry, the industry on which our empirical analysis focuses, spin-offs engaged in alliances with large and established partners, partners of similar type and size, and with public research organizations, often for different reasons. We seek to understand to what extent alliances of spin-offs with other firms (either large- or small- and medium-sized firms) affected their innovation performance and also how this performance may have been affected by their corporate or public research background. We find evidence that in general alliances of spin-offs with other firms, in particular alliances with large firms, increased their innovation performance. Corporate spin-offs that formed alliances with other firms outperformed public research spin-offs with such alliances. This suggests that, in terms of their innovation performance, corporate spin-offs that engaged in alliances with other firms seemed to have benefitted from their prior corporate background. Interestingly, it turns out that the negative impact of alliances on the innovation performance of public research spin-offs was largely affected by their alliances with small- and medium-sized firms.  相似文献   
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