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41.
Invasive animal pests reduce crop and livestock output, require management and control measures, and threaten native plants, animals and their habitat. The agricultural and management costs are often directly measurable. But the costs to protect threatened native plants and animals are harder to assess. The Rural Lands Protection Boards were the government agency in New South Wales that managed invasive animals. An analysis of their decisions provided the opportunity to estimate the costs of protecting native species. The number of native plants and animals threatened by invasive pests was modelled against the expenditure, area, pest abundance, climate and location of 38 Board districts. There was a strong negative relationship between the number of threatened native species and Board expenditure. This relationship was interpreted to estimate the marginal cost of protecting a threatened native species, the downward shift in the supply curve necessary to protect all threatened native species, and the gains from the shift in the form of cost savings in the continued protection of non-threatened native species. These results value some of the costs that invasive animal pests impose on the environment.  相似文献   
42.
The aim of this paper is to take a holistic perspective to explore levels of cycling and opportunities and barriers to increase children’s safer cycling in disadvantaged areas in England. The study was one part of a larger study which explored the factors underlying the high level of road traffic casualties especially among children in the most disadvantaged areas of England and to explore how this impacts on mobility and quality of life. The methods involved a cross sectional survey comprising school based questionnaire surveys with children aged 9-14 and focus groups with parents who had children within this age range. The surveys were conducted in 2007 and the focus groups during 2008. 4286 children completed the survey and eight focus groups were held. Bike ownership (77%) was high, use in previous week moderate (39%) but only 2% cycled to school. Ownership was significantly lower in minority ethnic groups. Despite young children’s strong preference to travel by cycle (30%) than walk or go by car, most parents felt it was too hazardous. It is unlikely that these findings would be any different from the rest of England, however the combination of environmental and social factors may elevate the risks for young cyclists in these areas. This paper concludes that a number of barriers exist to increasing levels of cycling among children living in disadvantaged areas particularly amongst ethnic groups. These barriers could be addressed by environmental modifications to reduce speeds and by reducing the levels of antisocial driving and riding in residential areas and around destinations where children travel, by providing cycle training to improve children’s skills and parent’s confidence, and by providing secure storage facilities for bikes. Until these barriers are addressed it is unlikely that cycling will increase despite the strong preferences children have to travel by bike. Such preferences to cycle provide an opportunity for local authorities to act on.  相似文献   
43.
This paper reports on a system dynamics simulation model which was developed to study the diffusion of medical technologies but which should be applicable to other sorts of technologies as well. The model addresses both the adoption and the changing extent of use of an evolving, product-based technology and also endogenously accounts for changes in actual and perceived performance. Two specific medical case studies provide background to the model and are used for testing the model's ability to reproduce various aspects of historical behavior. The model's relatively complex structure is presented in the form of influence diagrams showing major flows and relationships. The paper concludes with a discussion of contributions and possible future uses and modifications of the model.  相似文献   
44.
This paper examines, via real data, some well known models for technology substitution analysis. We propose a family of data-based transformed models that will include the models under examination as special cases. The basic thrust of the paper is the recognition that for technology substitution analysis, the observations are time series data and hence are not independent. Also, the functional form of the model should be determined by both theoretical considerations as well as the data on hand. This suggests that the traditional ordinary least squares procedure used in estimating the parameters and the resulting forecasting procedures are not adequate. The existing models examined here are Fisher–Pry, Gompertz, Weibull, and Normal. We stress the statistical aspects of the models and their relative merits in terms of predictive power. The criteria used for the purpose of comparison are the mean squared deviation and the mean absolute deviation of the predicted values compared with the actual observations.  相似文献   
45.
46.
As cities look at various industries to strengthen their economies, officials have begun to examine conventions and gaming more closely as they have often been considered “recession-proof.” This study utilizes time series regression to analyze the effects of convention attendance and hotel occupancy on monthly gaming revenues for Las Vegas from 2002 to 2013. Three commonly held opposing viewpoints in trade literature are that conventions reduce, augment, or complement gaming. These viewpoints produced the hypotheses for this study. It was found that convention attendance had no significant relationship with gaming revenue; however, citywide hotel occupancy was found to have a significant positive relationship with gaming revenue. This finding rules out the reduction and augmentation hypotheses.  相似文献   
47.
A recent paper by Hardaker et al. (The Australian Journal of Agricultural and Resource Economics, 48, 2004a, 253) and book by Hardaker et al. (Coping with Risk in Agriculture, 2004b) describe a procedure for determining an efficient set from among a set of random alternatives. This procedure, called stochastic efficiency with respect to a function (SERF), is claimed to make the same assumption concerning the risk aversion measures as does stochastic dominance with respect to a function (SDRF). This is claim is incorrect. SERF imposes an additional requirement on the risk aversion measures of the decision makers. Both procedures assume a lower and an upper bound on risk aversion, but SERF also assumes that all risk aversion measures are of the same functional form as these lower and upper bound functions. This additional strong requirement on risk preferences implies that the efficient set identified under SERF is usually smaller than that identified using SDRF.  相似文献   
48.
We examine variation in the rate of divestment by multinational firms from Burma. We argue that in addition to a set of firm‐level characteristics known to impact divestment decisions, firms are also influenced by characteristics of their home country and the divestment patterns of others. Using data on firms operating in Burma during 1996–2002, we model these multiple influences on firms to divest. Our results show that beyond firm‐level concerns, firms divest in response to the political characteristics of their home country, including protest, the level of political freedom, and transparency of institutions. We also find that the centrality of their home country in the network of intergovernmental organizations impacts divestment patterns in interesting ways. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
49.
University spin‐out (USO) companies play an increasingly important role in generating value from radical, generic technologies, but this translation requires significant resources from other players to reach the market. Seven case studies illuminate how relationships with each type of partner can be leveraged to help the firm create value. We find that most firms in the sample are aware of the importance of corporate partners and actively seek to cultivate these relationships, but may not be taking full advantage of the resources available through nonparent academic institutions and other USOs with similar or complementary technologies.  相似文献   
50.
Tourism development is a key feature of the neoliberal economic development model. Through a mix of state and private investment, Indigenous communities in Mexico are encouraged to transform local cultural and environmental resources into tourist consumption sites. The process results in a shift toward reliance on tourism, in place of farming, leaving households with few alternative earning strategies amidst fluctuating tourist arrivals and income, confounding the relationship between tourism and sustainability and questioning the utility of tourism as a sustainable tool for development. This article analyses a community-based Indigenous tourism project in a rural Maya village in Mexico's Yucatan, and discusses strategies employed at household level to navigate the arrival of tourism. Funding agencies assessed this project based on a triple bottom line metric that accounts for ecological health, financial sustainability, and its relationship to local social capital; however, these fail to account for differences between local and non-local conceptions of authenticity, indigeneity, and success. From a social perspective, the project has exacerbated existing tensions and has arguably widened the gap between the politically and economically powerful and less powerful, marginalized families in the community. Questions about policy, governance systems, and elite domination and kin group control are raised.  相似文献   
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