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41.
At the European level there is an increasing focus on how freight transport can be moved from trucks on roads to more environmentally friendly modes such as rail and ship. A large proportion of the transport services between OD pairs, however, cannot be substituted since there is only one alternative available. The paper investigates the magnitude of this “structural inelasticity” of modal substitution in freight transport due to a sparser layout of rail and ship-based freight networks compared to road. In the analysis we use a recent Scandinavian freight demand model covering more than 800 zones. We find that the structural inelasticity is very significant - in particular for transportation over less than 500 km. Moreover, the inelasticity varies greatly with commodity groups and between OD pairs, and it depends strongly on the port and rail infrastructure. The results suggest that pure charging instruments (road pricing for trucks) in many regions will have limited mode substitution impacts. However, if combined with structural changes in terms of improved infrastructure for rail and ship, impacts may be greater. 相似文献
42.
Arega D. Alene Abebe Menkir S. O. Ajala B. Badu-Apraku A. S. Olanrewaju V. M. Manyong Abdou Ndiaye 《Agricultural Economics》2009,40(5):535-550
This article assembles the results of three multicountry surveys on variety performance and adoption patterns to measure the impacts of maize research in West and Central Africa from 1981 to 2005, and uses cost data since 1971 to compute social rates of return on public investments in maize research in the region. Adoption of modern varieties increased from less than 5% of the maize area in the 1970s to about 60% in 2005, yielding an aggregate rate of return on research and development (R&D) investment of 43%. The estimated number of people moved out of poverty through adoption of new maize varieties rose gradually in the 1980s to more than one million people per year since the mid 1990s. Over half of these impacts can be attributed to international maize research at IITA and CIMMYT. The article concludes with a discussion of strategic options to enhance the impacts of maize research in the region. 相似文献
43.
Patterns in property values provide strong signals about the future and sustainability of land use. This paper analyzes the determinants of land value in an Amazonian frontier settlement. We estimate hedonic price functions to identify factors that affect the value of farm properties in the western Brazilian Amazon. Distance to market explains nearly one-third of the variation in farm value, as predicted by the von Thünen model. After controlling for location relative to the central market and for municipality, we find that investment in the farms (as reflected in the stocking rate of pastures and the establishment of home gardens) has the next largest impact on land value. The value per hectare of land is negatively related to total lot size, suggesting that any economies of scale are outweighed by the cost of accessing remote corners of large properties. We do not find that land values are related to available measures of biophysical factors or to historic or current land use. Our results do not identify any premium for forest cover or for land uses considered to be more sustainable than pasture on the property itself. However, farm values are affected by neighboring land cover, specifically, the extent of barren land. Thus, local knowledge of factors contributing to future productivity, as summarized in land values, confirms that soil exhaustion can lead to a general decline in property values, while investments in a property both as a homestead and as a farm can help sustain frontier settlements. 相似文献
44.
T. Efole Ewoukem O. Mikolasek J. Aubin M. Tomedi Eyango V. Pouomogne D. Ombredane 《国际农业可持续发展杂志》2017,15(2):208-222
In Sub-Saharan Africa, fish ponds are often an integral part of farming systems but have suffered from a lack of viability and sustainability. The present study aims to understand the strategies used by fish farmers to overcome economic and environmental constraints. In 2008 and 2009, fish farmers were surveyed in Central and Western Cameroon, and the fish production systems were classified by cluster analysis. Four broad types were identified according to the complexity of household operations. The development of extensive systems (large-scale and low-input) in rural areas of central Cameroon is induced mainly by abundant available land. For semi-intensive systems in both regions (small-scale and high-input in the Western Region, large-scale and high-input in peri-urban areas of the Central Region), horizontal integration is not sufficient to make fish production profitable and sustainable. More intensive fish farms tend towards vertical integration, in which farmers establish close links with input suppliers. Main causes of low productivity of semi-intensive systems (1–2?t/ha/yr) are both lack of knowledge of fish farming principles by farmers and lack of technical improvement by extension agents and researchers which need to consider the local complexity of farming systems to develop and intensify fish production. The adaptation of development strategies to socio-economic and environmental contexts is a necessity to hope for an increase in fish pond aquaculture production in Africa. 相似文献
45.
Is fertiliser use inconsistent with expected profit maximization in sub‐Saharan Africa? “Evidence from Nigeria” 下载免费PDF全文
Lenis Saweda O. Liverpool‐Tasie 《Journal of Agricultural Economics》2017,68(1):22-44
This article revisits a conventional wisdom that inorganic fertiliser use across sub‐Saharan Africa is too low. This expectation that more farmers should be using inorganic fertiliser, and at higher rates, implies it is profitable to use rates higher than observed if farmers are rational expected profit maximisers. We obtain consistent estimates of the effects of applied nitrogen on rice production. We find the yield response to applied nitrogen to be low in the main rice growing farming system. Farmer behaviour is not inconsistent with expected profitability which is limited by a low yield response to applied fertiliser, high transportation costs, and low selling prices for rice in rural areas. In particular, we do not find any farmers for whom applied nitrogen is profitable that are not using fertiliser in the study sample for each of our survey years (2010 and 2012). 相似文献
46.
Earnings Management through Specific Accruals and Discretionary Expenses: Evidence from U.S. Agribusiness Firms 下载免费PDF全文
Carlos J.O. Trejo‐Pech Richard N. Weldon Michael A. Gunderson 《Revue canadienne d'agroeconomie》2016,64(1):89-118
This study examines both accruals based earnings management (AEM) and real earnings management (REM) in U.S. agribusinesses. In particular, the focus is on agribusinesses that report low earnings quality, defined as firms with extreme level of accruals compared to their peers. The cross‐sectional modified Jones model (Jones 1991; Dechow et al 1995) is used to test for AEM. To capture REM practices, we implement the discretionary expenses model by Roychowdhury (2006). We find evidence of AEM and find no evidence of REM in agribusinesses. In addition, our results show that managers might be managing earnings through specific accruals doubtful accounts receivable provisions and special items. 相似文献
47.
Julie Carlson Ginger Zhe Jin Matthew Jones Jason O’Connor Nathan Wilson 《Review of Industrial Organization》2017,50(4):487-507
In 2015, the Federal Communications Commission (FCC) imposed common carriage regulation—so-called Title II requirements—on previously unregulated broadband Internet service providers. The regime shift was premised on the FCC’s findings that such rules had demonstrably yielded economic gains. This paper evaluates the FCC’s empirical arguments and finds them uncompelling. Adjustments for inflation or general economic trends eliminate the effects cited by the FCC. Moreover, contrary to the Commission’s assessment, mobile services and broadband markets have shown notable growth in response to deregulatory events that reduce Title II requirements. 相似文献
48.
49.
Is There Persistence in the Impact of Emergency Food Aid? Evidence on Consumption, Food Security, and Assets in Rural Ethiopia 总被引:1,自引:0,他引:1
We identify the impact of emergency food aid programs after the 2002 drought in rural Ethiopia on future welfare. Based on a difference-in-differences matching estimator, participation in food-for-work increases growth in total consumption and food consumption eighteen months after the drought. Separately, receiving free food raises growth in food consumption, but, surprisingly, negatively impacts food security. Food-for-work benefited households in the middle and upper tail of the consumption distribution, while the better-targeted free food program benefited the poorest. Evidence suggests these impacts demonstrate accumulated and persistent effects of food aid received in the first twelve months after the drought. 相似文献
50.
Designing and evaluating sustainable development pathways for semi‐subsistence crop–livestock systems: lessons from Kenya 下载免费PDF全文
Achieving the Sustainable Development Goals (SDGs) in African agriculture requires a better understanding why high levels of poverty and resource degradation persist in African agriculture despite decades of policy interventions and development projects. In this article, we hypothesize that policies need to account for the key features of the semi‐subsistence crop–livestock systems (CLS) in the region to become effective. The semi‐subsistence CLS are characterized by a high degree of biophysical and economic heterogeneity and a complex, diversified production system involving a combination of subsistence and cash crops with livestock. We investigated the potential for interventions proposed by the Government of Kenya to meet the SDGs by 2030. The analysis uses an integrated modeling approach designed to deal with the key features of these systems. A strategy that stimulates rural development, increases farm size to a sustainable level, and reduces distortions and inefficiencies in input and output markets could lead to a sustainable development pathway and achieve the SDGs for rural households dependent on CLS. 相似文献