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71.
72.
This paper explores differences in the bidding patterns of entrants and incumbents in road construction auctions. We find that entrants bid more aggressively and win auctions with significantly lower bids than incumbents. The differences in their bidding patterns are consistent with a model of auctions in which the distribution of an entrant's costs exhibits greater dispersion than that of an incumbent's and relations of stochastic dominance in the distributions do not persist for the entire range of estimated costs. We also find that more efficient firms bid, on average, more aggressively and firms with greater backlogs bid less aggressively.  相似文献   
73.
In this article the impact of technology education, as a new learning area (subject) in the curriculum, on in-service teacher education in South Africa is described in order to ascertain the extent of the impact. The research on which this article is based draws on a variety of experiences and observations in the field at grassroots level (in particular an outreach project in rural communities). The envisaged impact of technology education on South African schools, communities, teacher educators and teachers, the range of in-service teacher education that is required, and the impacts in urban and rural areas are discussed. Finally a number of concluding remarks are made about the extent of the impact of the inclusion of technology education in the new National Curriculum Statement and whether the situation has changed since the implementation of a pilot technology education project in 1998. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
74.
One Pleistocene mystery is why early North Americans eradicated their large, potentially domesticable animals (e.g., horses), whereas early Europeans did not. A commonly‐held hypothesis is that European species were evasive due to co‐evolution with hominids, whereas North American animals were naïve and unable to adapt quickly enough when experienced human hunters arrived from Eurasia. We explore this hypothesis with a paleoeconomic model of co‐evolution that integrates human hunting investments and wildlife population responses. We find that investments in hunting ability, based on the relative scarcity of prey species, could have mattered more than wildlife ‘naivety’ in explaining the extinction.  相似文献   
75.
In this paper we will analyze the relationship between the value and duration moments of a cash flow and movements in the yield curve. We will show that for changes in the yield curve which can be related to tn , the 1st order changes in the net present value of a cash flow are linearly dependent on the n + lth duration moments, and that the 2nd order changes are dependent on the sum of duration moments of order 2 n + 1 and 2 n + 2. We will use this relationship to tilt tracking portfolios so as to protect them against specific changes in the yield curve.  相似文献   
76.
Futures research includes the problem of generating reasonably exhaustive and plausible scenarios for a given topic, a problem for which there are no truly satisfactory solutions. This article reviews and evaluates a method, field anomaly relaxation, first put forward some 20 years ago. The evaluation is in the context of an illustrative study of political developments in Europe. The research reconstructs and further develops the method and concludes that it has something to offer for scenario generation. Its weaknesses are identified and suggestions for further research are made.  相似文献   
77.
The study examines the origins of technology important to improving productivity in the food-processing industries. Technology flows were measured both by patents in patent classes closely identified with six food industries, and by a sample of significant food-processing innovations. These data are consistent with the hypothesis that interindustry technology flows are the most significant determinant of productivity improvements in the food industries. These findings solve the enigma that the food-processing industries have enjoyed rapid improvements in productivity despite making very modest investments in research and development.  相似文献   
78.
79.
From the expected‐utility approach, relative risk aversion being smaller than one and relative prudence being smaller than two emerge as preference restrictions that fully determine the optimal responses of decisions under uncertainty to certain shifts in probability distributions. We characterize the magnitudes of relative risk aversion and relative prudence in terms of the two‐parameter, mean‐standard deviation approach. We demonstrate that this characterization is instrumental in obtaining comparative static results in the two‐parameter setting. We further relate our findings to the results in the expected‐utility framework.  相似文献   
80.
Neuroeconomics: Why Economics Needs Brains   总被引:7,自引:0,他引:7  
Neuroeconomics uses knowledge about brain mechanisms to inform economic theory. It opens up the “black box” of the brain, much as organizational economics opened up the theory of the firm. Neuroscientists use many tools—including brain imaging, behavior of patients with brain damage, animal behavior and recording single neuron activity. The key insight for economics is that the brain is composed of multiple systems which interact. Controlled systems (“executive function”) interrupt automatic ones. Brain evidence complicates standard assumptions about basic preference, to include homeostasis and other kinds of state‐dependence, and shows emotional activation in ambiguous choice and strategic interaction.  相似文献   
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