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211.
研究目的:探讨不同规模农户采纳秸秆还田技术的行为差异和影响因素。研究方法:采用Logistic模型对冀、鲁、皖、鄂4省1372份农户调查数据进行实证分析。研究结果:(1)农户的秸秆还田技术采纳行为存在规模经济效应;(2)地块数和区位条件是限制小规模农户采纳秸秆还田技术的客观因素,在土地规模短期不能扩大的情况下,秸秆还田技术不具备普适性是该项技术推广受阻的重要原因;(3)配备秸秆还田服务人员机构,有针对性地对小规模男性农户进行培训和指导,提高农户的经济收入和经济感知,能显著促进小规模农户采纳秸秆还田技术。研究结论:应从改善机械作业条件,促进土地适度规模经营;改进秸秆还田技术,降低技术采纳成本;培育秸秆还田社会化服务组织,提高农户认知等方面着手,有效推广秸秆还田的耕作技术手段。  相似文献   
212.
The establishment of deep-rooted perennial species and their processing for biomass-based products such as renewable energy can have benefits for both local and global scale environmental objectives. In this study, we assess the potential economic viability of biomass production in the South Australian River Murray Corridor and quantify the resultant benefits for local and global scale environmental objectives. We model the spatial distribution of economically viable biomass production in a Geographic Information System and quantify the model sensitivity and uncertainty using Monte Carlo analysis. The total potentially viable area for biomass production under the Most Likely Scenario is 360,728 ha (57.7% of the dryland agricultural area), producing over 3 million tonnes of green biomass per annum, with a total Net Present Value over 100 years of A$ 88 million. The salinity in the River Murray could be reduced by 2.65 EC (μS/cm) over a 100-year timeframe, and over 96,000 ha of land with high wind erosion potential could be stabilised over a much shorter period. With sufficient generating capacity, our Most Likely Scenario suggests that economically viable biomass production could reduce carbon emissions by over 1.7 million tonnes per annum through the production of renewable energy and a reduced reliance on coal-based electricity generation. Our analyses suggest that biomass production is a potentially viable alternative agricultural system that can have substantial local scale environmental benefits with complimentary global scale benefits for climate change mitigation.  相似文献   
213.
The article describes the development, purification, and validation of a reliable self-report scale designed to measure the Desire for Visual Aesthetics (DVA) in the store environment. There is limited literature on the subject and a measurement scale has eluded both academicians and practitioners that could help measure the need for aesthetics in the retailing environment and help marketers decide on the level and type of aesthetics for the different segments in the target market/s and also the different type of retail stores. We used 3 focus groups, 8 individual interviews, and 891 surveys to develop, purify, and validate the 9-item Likert type scale. We also provide evidence for dimensionality, reliability, and validity. The scale could be used by academicians and practitioners alike, and could replace single items to measure the concept.  相似文献   
214.
South Africa's sugar industry has long been distinguished by its large number of small‐scale sugarcane growers (SSGs) farming on ‘communal’ land and its peculiar privately administered regulatory structure. In recent years, however, the numbers of small‐scale growers have declined precipitously. This paper argues that the relationship between the rise and fall of SSG production and the industry's governing regulatory structure is closer than usually appreciated. The emergence of SSG production in the late 1970s and the 1980s can be traced to industry‐subsidized initiatives, disguised as small‐scale credit, to bring commercially inalienable Bantustan land into cane production with strong miller oversight. From the late 1980s to 1990s, however, the elimination of these subsidies encouraged millers to subcontract support to farmers, while simultaneously instigating an increase in SSG numbers by removing restrictions on grower registration. Although low rainfall is a central proximal factor in the rapid decline of the SSGs in the 2000s, their rapid increase was structurally fragile.  相似文献   
215.
Many environmental problems are due to damage caused by pollutants that accumulate with a time lag following their emission. In this study, we focus on nitrates used in agriculture, which can pollute groundwater many years after their initial application. A dynamic optimal control problem with heterogeneous farmers is proposed. The usual structural parameters such as the discount rate, the natural clearing rate and the lagged time interval between the occurrence of soil‐level pollution and the impact on groundwater are taken into account. We also examine pollution as caused by a continuous set of farms characterised by their individual performance index and by their individual marginal contribution to the pollution. The issue is further investigated by taking account of change in the information context, successively related to perfect information and to asymmetric information. As a result, when the delay between the spreading of N‐fertilizer and the impact on the aquifer increases, that is, the longer the lag, the steady‐state pollution stock and the steady‐state shadow price of the stock both increase. Moreover, we show that the optimal regulation may require a decreasing amount of fertilizer over time, even in the case of initial underpollution.  相似文献   
216.
This paper examines the cost structures of the leading integrated air cargo carriers, FedEx Express and UPS Airlines. A total cost model is estimated for the two carriers using quarterly data on domestic operations and costs over a nine-year period (2003–2011). The estimated model indicates that the integrated industry exhibits increasing returns to traffic density and constant returns to scale. Accounting for carrier-specific differences in cost structure and network size, FedEx Express is found to be more cost-efficient than UPS Airlines. Looking at the carriers individually, UPS Airlines exhibits substantial economies of traffic density and constant returns to scale while FedEx Express' cost structure is characterized by weak economies of density and constant returns to scale. The combined effect of returns to density and returns to scale on the cost structures of integrated carriers is captured by economies of size. Both FedEx Express and UPS Airlines exhibit economies of size, indicating that carriers in the integrated industry can be more cost efficient by making appropriate adjustments to their network size as their output grows. Moreover, the relative cost-efficiencies of the carriers are reversed when their network-size differences are not controlled.  相似文献   
217.
This study provides further empirical investigation, in the context of giant Japanese banks, of the recent claim by Pulley and Braunstein (1992, A composite cost function for multiproduct firms with an application to economies of scope in banking, Review of Economics and Statistics 74, 221–230), that their new composite model for the multiproduct cost function has important advantages over the separable quadratic, generalized translog and standard translog models. In addition to assessing the composite model's relative ability in measuring global scope and scale economies, the study also extends the P-B analysis to assess measurement of product-specific scope and scale economies, pairwise cost complementarities between outputs, changes in the marginal costs of outputs and technological change. The results appear to confirm P-B's chain. The persistent finding of scale economies for large Japanese banks is also investigated and confirmed.  相似文献   
218.
随着存款保险制度的推出以及金融机构退出机制的完善,国家声誉将逐渐退出银行无形资本。在激励相容的金融监管趋势下,特许权价值等市场约束力量会显著影响到商业银行的风险承担。在此逻辑基础上,以我国16家上市商业银行为研究对象,一方面探讨特许权价值影响下不同产权结构的商业银行的最优救助机制,另一方面通过最优救助临界指标,利用银行重组模型,推导合理的存款保险风险差别费率。  相似文献   
219.
在我国高等教育快速发展的同时,高等教育区域发展不均衡、资源配置不公平等现象越来越突出。采用熵权法从教育规模、经费投入、基础设施和师资力量四个维度构建地区高等教育综合发展指数,对2004—2013年我国地区高等教育发展水平进行全局空间自相关分析、局部空间自相关分析和三维趋势分析,结果表明:我国高等教育发展水平在总体上呈现显著的空间正相关特征,且空间关联性逐渐增强;虽然落后地区与发达地区的差距有所减小,但高等教育发展的空间异质性明显,落后地区仍然占很大比重。因此,我国高等教育发达地区未能有效发挥空间辐射和带动作用,空间溢出效应不明显,高等教育发展的空间结构有待改善。国家应避免高等教育区域差距继续拉大,落后地区应加快高等教育发展,发达地区应有效发挥辐射带动作用,努力缩小高等教育的空间差距。  相似文献   
220.
Akamatsu, Sato, and Nguyen (2006 Akamatsu, T., Sato, S., &; Nguyen, X. L. (2006). Tradable time-of-day bottleneck permits for morning commuters (in Japanese). JSCE Journal of Infrastructure Planning 62(4), 605620.[Crossref] [Google Scholar]) proposed a first-best pricing scheme based on the concept of bottleneck permits. The scheme allows permit holders to pass a bottleneck at specified times and is shown to be able to minimize social cost. However, the scheme is not always Pareto-improving in that it may harm some drivers. The objective of this study is to design Pareto-improving pricing scheme with bottleneck permits for a V-shaped two-to-one merge bottleneck. First, the paper formulates the morning commute model in the network and describes the arrival time choice equilibrium in the network with merging bottleneck. Secondly, we show that the first-best pricing scheme with bottleneck permits for this V-shaped network does not always achieve a Pareto improvement, with the cost of one group of drivers is increased by the permit pricing, a phenomena akin to the bottleneck paradox of Arnott, de Palma, and Lindsey (1993 Arnott, R., de Palma, A., &; Lindsey, R. (1993). Properties of dynamic traffic equilibrium involving bottlenecks, including a paradox and metering. Transportation Science 27(2), 148160.[Crossref], [Web of Science ®] [Google Scholar]). We propose three implementations of bottleneck permits for Pareto-improving: (1) merging priority rule is included in the bottleneck permits scheme by creating different market for each origin; (2) the permit revenues are refunded as monetary compensation to drivers whose cost is increased; and (3) the permit revenues are used to expand bottleneck capacity. For each implementation, we derive their equilibrium solutions and demonstrate that the Pareto improvement is achieved and social cost is decreased by using the permit revenues for expanding the bottleneck capacity.  相似文献   
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