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1.
Several complicating issues arise in evaluating the returns to research into varietal improvements for perennial crops compared with annual crops. We elucidate and address these issues in the context of a case study of research aiming to develop varieties that are resistant to Pierce's disease (PD) of grapevines. PD imposes costs of over $100 million per year on the California grape industry, even with public PD control programs in place. Research projects to develop PD resistant varieties of grapevines are at various stages of completion. We describe the economic problems posed by PD, document the research programs undertaken to address the disease and present an economic assessment of the returns to the investment, which are conditional on other policies. Using a simulation model of the market for California winegrapes, we estimate the benefits from research, development and adoption of PD‐resistant vines as ranging from $4 million to $129 million annually over a 50‐year horizon, depending on the length of the R&D lag and the rate of adoption. In addition to these specific quantitative results the paper offers insight into the broader question of economic evaluation of damage‐mitigation technology for perennial crops.  相似文献   

2.
Does agricultural extension pay?   总被引:1,自引:0,他引:1  
Compared to studies evaluating the benefits from agricultural research, there are relatively few empirical studies of the net economic benefits of agricultural extension, and even fewer that consider both public and private sector extension effort. In this study we examine regional differences in the adoption of lupins in Western Australia (WA) in order to estimate the net economic benefits of public and private sector extension. Impacts of extension and other variables on adoption were analysed for 40 shires using multivariate regression analysis. The results suggest that both public and private extension activities influenced farmer uptake of lupins, particularly by bringing forward the start time of the diffusion curve. Economic benefits of extension, based on the statistical analysis, were combined with costs of extension estimated from public sector records and surveys of private sector extension agents and used to estimate the net present value of extension investments by the public and private sectors in the study area.  相似文献   

3.
This paper presents an improved approach for predicting the speed and ceiling of technology adoption, which is a crucial information for research priority setting. In the models it is assumed that both the speed and ceiling of adoption depend on the perceived characteristics of technologies. Knowing the characteristics that have determined adoption in the past provides relevant information about the characteristics which will enable new technologies to be quickly and widely adopted in the future. Using a case study from Meru District in Kenya, it is shown that relative investment, relative risk and relative complexity significantly influenced the speed and ceiling of adoption of dairy technologies in the past. These empirical results are used to predict the speed and ceiling of adoption of potential new dairy technologies to be developed by the Dairy Cattle Research Programme (DCRP) of the Kenya Agricultural Research Institute (KARI). The approach is theoretically sound and based on empirical evidence. It clearly distinguishes promising technologies from less promising technologies and is transparent to participants in priority setting exercises. Allowing for the participation of all interest groups within the research system, the approach improves the quality of the assessment and hence the credibility of results.  相似文献   

4.
A framework for comprehensive integrated assessment of environmental projects is developed and applied in partnership with a regional environmental body. The framework combines theory with practice, bringing a pragmatic and efficient approach to the rigorous assessment of projects for a large number of environmental assets in the north central region of the state of Victoria, Australia. The approach is codified as the Investment Framework for Environmental Resources (INFFER). The analysis assisted the environmental body to make strong business cases for a number of environmental projects, resulting in funding for those projects. Key features of the study include extensive participation of decision makers and stakeholders, integration of a comprehensive set of information about projects, explicit assessment of uncertainties and information gaps, and analysis of the most appropriate policy mechanism for each project. The process of applying the framework involved four steps: identification of around 300 important environmental assets in the region, filtering the list of assets to remove those that are less likely to provide opportunities for cost-effective public investment, development and detailed assessment of projects for a subset of assets, and negotiation of funding for projects. Implications for land-use policy include that environmental projects vary widely in their cost-effectiveness, requiring careful targeting of funds if environmental benefits are to be maximised. Many existing environmental programs use simplistic analyses to support decision making, resulting in missed opportunities for substantially greater environmental benefits. Promoting adoption of improved analytical methods is very challenging, requiring changes in mind-set and culture in environmental organisations. Widespread adoption is unlikely unless funders create incentives by rewarding those project proponents who undertake rigorous and comprehensive project assessments that focus on achievement of environmental outcomes.  相似文献   

5.
Strategic priorities are assessed tor the agricultural research system in Zimbabwe in a situation characterized by multiple objectives, farm types, and agro-ecological zones. Economic surplus analysis is used to rank research programs by commodity and research program areas in total and disaggregated by large and small larms in high and low potential regions. No funding, current funding, and 50% more funding are allowed tor each program in the analysis. An optimal research portfolio is developed, first with all weight placed on efficiency, and second with increasing weights placed on benefits going to small-holder farmers. Even with no additional weight placed on small holders. lesearch programs for both small farms and low potential areas enter into the optimal research portfolio. As more emphasis is given to small holders, the reduction in overall efficiency gained due to research is relatively modest, Maize and cotton were the highest ranked commodity research programs of the 36 commodities considered for both large and small larms. Agronomy and soils research are relatively more important for small holders, while plant breeding and crop protection are relatively more important for large-scale farmers. priority selling: Economic surplus and mathematical programming analysis.  相似文献   

6.
Considerable agreement exists among researchers, development practitioners, and policymakers regarding the goals of sustainable agricultural intensification (SAI). They include: achieving agricultural productivity growth, household food security, and improved rural livelihoods and employment, while simultaneously mitigating environmental degradation. However, the multiplicity of these objectives, as well as the choice of approaches to achieving them and the site‐ and context‐specificity of specific technological and institutional interventions, assures that the research and policy challenges to achieving SAI will remain considerable. This article summarizes the contributions of the articles in this Special Issue in four areas of the literature. First, labor market constraints, the labor intensity of specific agricultural technologies and practices, and labor's substitutability, or complementarity, with other inputs are shown to widely influence their viability and related input efficiencies. Second, the articles identify specific tradeoffs and synergistic relationships that arise in the attainment of these multiple goals stemming from technologies, management practices, and policies introduced under specific agroclimatic, market, and institutional conditions. Third, these papers contribute to the literature on agricultural technology adoption by furnishing additional empirical evidence on the determinants and effects of investment behavior and adoption of specific technologies and management practices. Finally, the articles in this Special Issue emphasize that there is no single policy nor technological, management, or institutional innovation that unambiguously promotes SAI. Preferred policies must be contextualized and sensitive to initial biophysical, market, and institutional conditions.  相似文献   

7.
Adoption rates of improved or modern varieties (MV) of sorghum in eastern Ethiopia are generally low. Although these MV may represent an effective means of coping with droughts, given their early maturing traits, landraces could prove to be more drought‐tolerant and better adapted to marginal production conditions. Whether MV adoption is a risk reducing technology is very much an empirical question which this article investigates using a unique dataset from eastern Ethiopia in a year of extreme weather conditions. Results show that risk‐factors coupled with access to markets and social capital drive farmers’ decisions to adopt MVs. On the one hand, it appears that farmers use MVs to mitigate moderate risks. On the other hand, farmers who have been most vulnerable to extreme weather events are less likely to use MVs suggesting that MV adoption does not necessarily represent an effective means of coping with drought. Finally, findings show that MV growers are more likely to be affected by sorghum failure once controlling for exogenous production factors.  相似文献   

8.
While intervillage differences in the adoption of modern rice varieties (MVs) are explained mainly by environmental variables, rather than by socioeconomic factors, relative factor prices are the most important determinants of the adoption oflabour-saving technologies. There is no indication that MV adoption is correlated with the adoption of tractors and threshers as well as cropping intensities. Adoption of direct seeding, however, appears to be associated with MV adoption.  相似文献   

9.
This article illustrates a methodology for assessing economic returns to a publicly funded breeding program in the presence of private sector investments, and spill‐ins from other contemporary public institutions and past research efforts. The approach consists of determining yield gains from bean improvement research; applying these yield gain estimates to measure benefits attributable to different institutional players and time periods; and then assessing the benefit‐cost ratios of investments in a bean improvement program since 1980 by Michigan State University (MSU). The results indicate that investments in MSU's bean breeding program have yielded benefits to costs ratio in the range of 0.7 to 2.2, depending on the attribution rule used to estimate the benefits. The estimated benefit/cost ratios reported in this study are lower‐bound estimates, as they do not account for potential benefits from area planted to MSU varieties outside of Michigan (spillover effects), which was 1.5 times greater than the area planted to MSU‐bred varieties within Michigan in the period 1998–2002. The implications of the increasingly privatized bean seed markets for the role of public sector research in bean improvement research are discussed.  相似文献   

10.
The paper tests a political economy theory of simultaneous government decision‐making on income redistribution through commodity policies and on public research investment in agriculture. We use data from 37 countries on agricultural protection and public agricultural research expenditures (PARI). The empirical results are consistent with the political economy hypotheses. The analysis suggest that structural changes in the economy have important effects on the political incentives for governments not only to subsidize or tax farmers, but also to invest in public agricultural research. Furthermore, the analysis supports the hypotheses that the impact of such structural changes on government decision‐making on PARI is non‐linear and conditional on other factors. Regarding the impact of political institutions, the results suggest that more democracy neither leads to more distortionary transfers (agricultural protection), nor to lower investment in public goods (PARI). ©2000 Elsevier Science B.V. All rights reserved.  相似文献   

11.
Over the past decades, growth in foreign direct investment (FDI) has stimulated significant attempts at developing theories that explain this trend. One line of this research explores the relationship between exchange rates and FDI. There is no consensus about the nature of this relationship in either the theoretical or empirical work. In this article, we critically appraise this body of work, and find the theoretical studies to be making ground in exploring the complexities of FDI, but the empirical evidence to be constrained by data problems.  相似文献   

12.
This paper reports the results of a study undertaken to estimate the economic impact in developing countries of efforts by the International Maize and Wheat Improvement Center (CIMMYT) to breed leaf rust resistant spring bread wheat varieties since 1973. The challenge in estimating these benefits lies in the pathogen's ability to mutate to new races, which may infect previously resistant varieties. Genetic resistance, rather than fungicide application, is the principal means of controlling leaf rust in developing countries. Whereas productivity enhancement is often estimated in terms of yield gains and increased supply, productivity maintenance is measured in terms of the yield losses avoided by the research investment. The internal rate of return on CIMMYT's research investment was estimated at 41%. When discounted by 5%, the net present value was US$ 5.36 billion in 1990 dollars, and the benefit‐cost ratio was 27:l. These findings emphasise the economic importance of maintenance research in crop breeding programs.  相似文献   

13.
This study offers a "best evidence" approach to summarizing recent benefit-cost analyses of international agricultural research in Africa. First, from an extensive literature review and the resulting global inventory of impact studies, 23 studies are identified that calculate aggregate rates of return for Consultative Group on International Agricultural Research (CGIAR) and partner investments in Sub-Saharan Africa (SSA). These studies are then appraised against a review framework consisting of principles, criteria, and indicators for study rigor. Subsequently, the economic benefits reported by studies grouped on the basis of its analytical rigor are aggregated and set against total investment by the CGIAR and national agricultural research systems to determine if the total investment to date can be justified by documented benefits under a range of assumptions. As a result, the study finds that aggregate investment is justified under a fairly wide range of suppositions. Under all scenarios, the vast majority of documented benefits stem from a relatively limited array of activities with a majority of benefits stemming from biological control (80%). Close to 20% of total benefits result from crop genetic improvement, and less than 1% result from all other activities. The implications of these results for research investment strategies in SSA and impact assessment are discussed.  相似文献   

14.
目的 种养分离的农业发展方式对生态环境造成严重破坏,是不可持续的发展方式,为重构种养一体化农业循环链条,促进农业健康可持续发展,通过实地调研,分析了中国生猪养殖场种养一体化现状,并从经济效益、社会效益和生态效益方面确定了14项综合效益评价指标,从实证角度对种养一体化农业系统的综合效益进行评价。方法 文章综合运用层次分析法和熵值法测算综合效益评价指标的权重,利用线性加权求和的方法对生猪养殖场种养一体化综合效益进行评价。结果 研究发现:在评价指标的权重方面,生态效益与社会效益的权重已经高于经济效益权重,说明当下社会更加注重生态和社会效益的发展;种养一体化农业系统的综合效益值明显高于非种养一体化,小、中、大规模的生猪养殖场种养一体化综合效益值分别是非种养一体化的1.16、1.20和1.17倍;综合效益值随养殖规模扩大呈现出先增加后减小的趋势,且养殖规模为1 300头左右时综合效益值最高。结论 虽然种养一体化农业系统的综合效益高于专业化农业生产,但在生猪养殖场种养一体化中仍然存在种养失衡、种养协作微弱等问题,尚未达到系统最优化,因此从种养平衡、养分管理体系建设、提高沼气工程利用率和优化种植结构方面提出对策建议。  相似文献   

15.
By now new modern rice varieties (MVs) with multiple pest and disease resistance have completely replaced early MVs, such as IR5 and IR8, except in a few areas of Asia. This study attempts to identify the changing impacts of ‘first-generation’ and ‘second-generation’ MVs on productivity in rice farming by estimating the yield function, while correcting selectivity bias arising from the choice of varieties. For this purpose, we used farm-level survey data collected for eleven cropping seasons in Central Luzon in the Philippines from 1966 to 1990. We found that while the yield advantage of first-generation MVs over traditional varieties was limited, the yield-increasing effect of second-generation MVs over first-generation MVs was highly significant. In particular, the adoption of improved MVs significantly contributed to yield growth under the irrigated condition and during the dry season. Thus, we conclude that the Green Revolution would not have been revolutionary without the development and the diffusion of second-generation MVs with multiple pest and disease resistance.  相似文献   

16.
This paper describes the evolution of a newly emerging smallholder maize paradigm in southern Africa beginning in 1996. This new paradigm involves the breeding, extension, and adoption of a new generation of open-pollinated ‘flinty’ maize varieties that specifically address the needs of southern African smallholder farmers for seed varieties that can be replanted (recycled) and that resist drought and low fertility problems increasingly common in southern Africa. The described mechanism is the extension and breeding work of the Southern Africa Drought and Low Fertility programme (SADLF) of the Centro Internationale por la Mejoridad de Maize y Trigo (CIMMYT). This paper explains the devolution of southern African maize production in the past two decades from centralized large-scale producers to smallholder farms, signalling a shift in research and plant breeding needs. The research/extension approach described here had profound consequences beyond the technical benefits of screening maize varieties for tolerance to stress; it empowered small-scale farmers to become informed consumers of agricultural technology. The transformation of the smallholder from a passive consumer to one actively seeking the best opportunity and seed to produce food, create economic opportunities and address local social conditions is an important development in the history and sustainability of maize production in southern Africa, and one consistent with modern African history of economic liberalization in the global food economy.  相似文献   

17.
Small ruminanl research carried out by the SR-CRSP on management, nutrition and reproduction was developed and evaluated through an Outreach Pilol Program in West Java, Indonesia. On-farm testing indicated that introduction of different management practices could increase birth rale and survivability of Javanese Thin Tail sheep. This article presents results from an assessment of research investments that measures the potential returns from this technological package, with various adoption and spillover effects, weighs the benefits against the research and training costs of the SR-CRSP, and looks at distribution of benefits among consumers and producers of sheep in Indonesia. The rate of return in the most conservative scenario was 19%, with potential short-run benefits exceeding the costs incurred by breeding and nutrition research, and training of 23 masters and doctoral students in 10 years. Market conditions favor producers in the distribution of benefits.  相似文献   

18.
Agroclimatic conditions and agricultural research and development (R&D) including plant breeding activities by the public sector are some of the most significant exogenous factors in the agricultural sector. However, the effects of the interactions between these two sets of factors on agricultural productivity have not been studied widely in developing countries, despite potentially important implications on their plant breeding strategies. Using three‐wave panel data of agricultural households in Nigeria and spatial data on various agroclimatic parameters, we show that agricultural productivity and technical efficiency at the agricultural household level is significantly positively affected by the similarity of agroclimatic conditions between locations where agricultural households are located, and locations where major plant breeding institutes are located. These results hold after controlling for various socioeconomic characteristics of these households, including their physical distances to the breeding institutes. Findings are robust across parametric and nonparametric specifications such as Data Envelopment Method, and after addressing potential endogeneity of agroclimatic similarity and agricultural inputs variables in the production function. Productivity effects due to the locations of plant breeding institutes and resulting agroclimatic similarity can be potentially sizable given Nigeria's past productivity growth speed.  相似文献   

19.
中国农业支持水平衡量与评价   总被引:2,自引:0,他引:2  
本文运用OECD的方法对我国1994—2003年的农业支持水平进行了实证分析。结果表明,我国农业支持水平总体呈上升趋势。20世纪90年代后期农业基础设施投资的大量增加、粮食保护价收购政策的实施使得农业生产者支持水平从2000年起由负向正转变。但是与世界发达国家相比,我国的农业支持水平依然很低,政府应该进一步加强对农业的支持和保护力度。  相似文献   

20.
Returns to investment in wheat breeding research in Nepal were estimated for two periods: (1) the Green Revolution period (1960–1990), when modern semidwarf wheat varieties first appeared and spread throughout the country, and (2) the post-Green Revolution period (after 1990), when first-generation modern varieties will be replaced by newer materials. Major benefits of the Nepalese wheat breeding program have included maintenance of disease resistance and faster dissemination of exotic germplasm. Attractive rates of return to investment in wheat breeding have been due in part to Nepal's ability to capture spillover benefits from neighboring countries and from international agricultural research centers.  相似文献   

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