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71.
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This paper illustrates how occasionally binding credit constraints can be quantitatively important to delivering business-cycle asymmetries. An empirical exercise suggests that countries display some business-cycles asymmetries, and an open-economy real business-cycle model is assessed where an international borrowing constraint binds occasionally. In the model, downward movements with a slack constraint are sharper and quicker than upward movements with a binding constraint, and this can deliver asymmetry over the business cycle. The model is calibrated to Canadian data and suggests that a necessary ingredient for asymmetry is a high initial level of foreign debt.  相似文献   
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This study uses employment data to examine why some industries host more new high-growth firms than others. Using a unique data base of 201 industries over a 15-year period, we find that increases in the proportion of employment of scientists and engineers in industries are positively associated with counts of fast-growing new firms; however, we do not detect a relationship between fluctuations in the proportion of employment in sales and production occupations and counts of fast-growing new firms. The findings suggest that technological innovation is an important determinant of entrepreneurial opportunity. Further, they suggest that private new firms are an important means of organizing commercial innovation and that new firms may be less constrained by complementary assets than has been previously understood.  相似文献   
75.
The future demand for land for mining and quarrying will be affected by a large number of economic, technological, environmental and social issues within the UK. Global developments also have a role to play. Although mining and quarrying account for only 0.9 per cent of the land area of England, the impact of this activity is considerable. Minerals are essential to the economy, for energy, construction, infrastructure and manufacturing, while their extraction has effects on the environment and on public perception. This paper examines current scientific understanding of the context of mining and quarrying, with particular reference to its impact on land use, along with the spatial relationship between minerals – which can only be worked where they occur – and other forms of land use and designation in the ‘post-industrial’ landscape of Britain. Looking out to 2060 and beyond, developments which may influence demand for minerals include climate change mitigation and adaptation; energy, food and raw material security; and new construction, manufacturing, recycling and re-use technologies. Factors influencing the supply side include the structure and ownership of the mining and quarrying industry, new extraction, processing and environmental technologies, ecosystem service provision, societal attitudes and land access. Although prediction carries a high level of uncertainty, continuous development of the regulatory framework is, and will remain, a major and pervasive factor in the relationship between mining and quarrying and land use.  相似文献   
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推广转基因抗虫棉对次要害虫农药施用的影响分析   总被引:3,自引:0,他引:3  
本研究的主要目的是分析在转基因抗虫棉有效控制棉花主要害虫(棉铃虫)、减少农药施用之后,可能导致的对棉花次要害虫的影响。通过多年的棉农生产跟踪调查和计量模型分析,研究结果表明,近年来棉农用来控制次要害虫的农药施用量有所增加,应引起有关部门的重视,但它的农药施用量远远小于采用转基因抗虫棉后整体减少施用的农药量;研究还发现,转基因抗虫棉在控制主要害虫农药施用量的减少,不是导致次要害虫农药施用量增加的主要原因,它仅仅能解释次要害虫农药施用增加量的一小部分。  相似文献   
78.
A double hurdle statistical analysis of 250 farms in the Tigray region of Ethiopia reveals different causal factors for soil conservation adoption versus intensity of use. Farmers' reasons for adopting soil conservation measures vary sharply between stone terraces and soil bunds. Long‐term investments in stone terraces were associated with secure land tenure, labour availability, proximity to the farmstead and learning opportunities via the existence of local food‐for‐work (FFW) projects. By contrast, short‐term investments in soil bunds were strongly linked to insecure land tenure and the absence of local food‐for‐work projects. Public conservation campaigns on private plots reduced adoption of both stone terraces and soil bunds. Whereas capacity factors largely influenced the adoption decision, expected returns carried more influence for the intensity of stone terrace adoption (measured as metres of terrace per hectare). More stone terracing was built where fertile but erodible silty soils in higher rainfall areas offered valuable yield benefits. Intensity of terracing was also greater in remote villages where limited off‐farm employment opportunities reduced construction costs. These results highlight the importance of the right kind of public interventions. Direct public involvement in constructing soil conservation structures on private lands appears to undermine incentives for private conservation investments. When done on public lands, however, public conservation activities may encourage private soil conservation by example. Secure land tenure rights clearly reinforce private incentives to make long‐term investments in soil conservation.  相似文献   
79.
Fertilizer Demand in China's Reforming Economy   总被引:5,自引:0,他引:5  
  相似文献   
80.
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