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81.
82.
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   
83.
84.
This study examines the perceived usefulness of alternative spatial and tree-based similarity scaling techniques in a market analysis task. These techniques are typically evaluated on their ability to fit or explain customer input data. The psychological reaction of individuals who use these techniques to analyze markets has been largely ignored. The study reveals that spatial representations are perceived as more useful than tree-based clustering techniques, even though the latter provide a better fit to customer perceptions. The results have implications for both the use and development of scaling techniques in psychology and marketing. © 1996 John Wiley & Sons, Inc.  相似文献   
85.
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   
86.
Fertilizer Demand in China's Reforming Economy   总被引:5,自引:0,他引:5  
  相似文献   
87.
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   
88.
Recent policy from the European Union has attempted to justify social tourism initiatives on the basis that they lead to a more sustainable tourism industry. However, the majority of latest research in the field has been focused on the benefits for participants, with the addition of some evidence on the economic impacts of such programmes on destinations, which have pointed towards sustainability outcomes including: a longer tourism season, more even spread of demand, and longer periods of employment for tourism workers. Yet there is a lack of direct evidence linking such programme to these outcomes. This paper aimed to explore this important disconnect between policy assumptions and evidence-based outcomes through an analysis of the deseasonalising effects of the Spanish social tourism programme for older people. The research found that this programme does have an effect on the seasonal nature of employment and economic activity in most regions studied, but that the huge volume of demand from international tourists in the high seasons masks the quantitative effects in the regions with the highest seasonal concentration of international tourists. Recommendations for policy and practice in sustainable tourism are made that are transferable to many countries and regions that adopt social tourism programmes.  相似文献   
89.
This paper examines how environmental resources and costs feature in business models of small- and medium-sized tourism enterprises (SMTEs). Several studies have pointed to the generally positive nature of the relationship between the economic and environmental performance of tourism firms. Yet, although business models act as a vector between these aspects of firm performance, they have been overlooked in sustainable tourism discourse. The paper reports findings from discussion groups of SMTE businesses in South West England during the global economic downturn. Environmental costs and cost control were afforded relatively little importance in terms of value creation; conversely, there was a strong and predictable emphasis on revenue generation. Indirect tactics emerged for dealing with guests’ environmental behaviours which reflected this prevailing commercial logic. Green credentials were routinely de-emphasized, sometimes regarded as liabilities, in a form of greenhushing. Responses were framed by reference to social media and how online reviews may negatively impact on future value capture. Conceptually, the business model emerged as an important lens for understanding how environmental resources and costs were valourized. The paper highlights the need to ensure that contemporary approaches to environmental management in SMTEs reflect the current and fast-changing conditions that frame business models.  相似文献   
90.
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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