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1.
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   
2.
Growing concern for poverty in the face of declining agricultural research budgets has increasingly required formal priority setting of public agricultural research in developing countries to ensure that scarce research resources are allocated in ways that will have the greatest impact on the poor. This paper assessed the potential impacts of alternative commodity research programs on poverty reduction in three agro-ecological zones of Nigeria and identified strategic agricultural research priorities in the three zones. The paper discusses the poverty reduction-based priorities and their role in facilitating dialogue between research managers and policymakers aimed at sharpening the focus of agricultural research to achieve poverty reduction objectives in Nigeria.  相似文献   
3.
This article examines the magnitude and sources of yield variation among adopters of improved cowpea varieties in northern Nigeria promoted through farmer‐to‐farmer diffusion. The results reveal important efficiency differences between the lead farmers who have contacts with breeders and the follower farmers who get technology and information from the lead farmers. Differential adoption of the package of seed, insecticide, fertilizer, and recommended cereal‐cowpea cropping pattern provides much of the explanation for yield variation among adopters. The component often missing, and hence accounting for much of the yield variation, is the crop management technology relating to the cereal‐cowpea cropping pattern. No efficiency variation is attributed to the source of technology and information, such as whether improved cowpea was obtained from breeders or lead farmers. Technology source has a rather indirect influence on efficiency through its effect on package adoption where breeders promote greater package adoption among the lead farmers than the lead farmers do among the follower farmers. Possible ways of disseminating crop management technological information through the farmer‐to‐farmer technology diffusion are recommended to better exploit the yield and profitability potentials of improved cowpea varieties in northern Nigeria.  相似文献   
4.
While it is widely recognized that agricultural research is a key driver of broad-based technological change in agriculture that benefits the poor in many different ways, little is known about its aggregate impacts on productivity growth and poverty reduction in sub-Saharan Africa (SSA). Using a polynomial distributed lag structure for agricultural research within a simultaneous system of equations framework, this paper first demonstrates that agricultural research contributes significantly to productivity growth in SSA. Productivity growth is again shown to raise per capita incomes, with income increases finally having significant poverty-reducing effects. With an aggregate rate of return of 55%, the payoffs to agricultural research are also impressive. Agricultural research currently reduces the number of poor by 2.3 million or 0.8% annually. While the actual impacts are not large enough to more than offset the poverty-increasing effects of population growth and environmental degradation, the potential impacts of agricultural research are far greater. Apart from low research investments, SSA faces several constraints outside the research system that hinder realization of potential research benefits. The results show that doubling research investments in SSA would reduce poverty by 9% annually. However, this would not be realized without more efficient extension, credit, and input supply systems.  相似文献   
5.
This paper assessed the effects of transactions costs—relative to price and non-price factors—on smallholder marketed surplus and input use in Kenya. A selectivity model was used that accounts for the effects of transactions costs, assets, technology, and support services in promoting input use and generating a marketable surplus. Output supply and input demand responses to changes in transactions costs and price and non-price factors were estimated and decomposed into market entry and intensity. The results showed that while transactions costs indeed have significant negative effects on market participation, institutional innovations—such as group marketing—are also emerging to mitigate the costs of accessing markets. Output price has no effect on output market entry and only provides incentives for increased supply by sellers. On the other hand, both price and non-price factors have significant influence on adoption and intensity of input use. Overall, the findings suggest that policy options are available other than price policies to promote input use and marketed surplus. The paper concludes with implications for policy to induce greater input–output market participation among smallholders in Africa.  相似文献   
6.
We use DNA‐fingerprinting to estimate the poverty reduction effect of adoption of improved cassava varieties in Nigeria. We estimate the counterfactual household income distribution of cassava producers by combining farm‐level treatment effects with a market‐level model. Our results suggest that adoption of improved cassava varieties has led to a 4.6 percentage point reduction in poverty, though this is sensitive to the measurement of adoption status. Therefore, accurate measurement of adoption is crucial for a more credible estimate of the poverty reduction effect of adoption. Our analysis also suggests that farmers who are more likely to be adopters are also likely to face higher structural costs. Addressing structural barriers that make improved technologies less profitable for the poor would therefore be important to increase the poverty reduction effect of improved cassava varieties.  相似文献   
7.
8.
Achieving sustainable food security and increased farm income will depend on how efficient production systems are in converting available inputs to produce outputs. Using data from Malawi, we estimate a Bayesian directional technology distance function to examine the relationship between farm size and technical efficiency. Our results support the existence of an inverse relationship between farm size and productive efficiency, where small farms are more efficient than large farms. On average, farms exhibit inefficiency levels of 60%, suggesting that productivity could be improved substantially. Improving productive efficiency and food security will require farms to operate in ways where the size of cultivated area is matched by nonland production inputs such as labor, fertilizer, and improved seeds. The results highlight the need for policies that could incentivize farmers to adopt productivity‐enhancing technologies and, where possible, to allocate excess land to lease markets.  相似文献   
9.
This paper estimates a more efficient version of an endogenous switching regression model to examine the effects of farmer education—schooling and extension contact—on cowpea production under traditional and improved technology in northern Nigeria. The results revealed significant productivity-enhancing effects of schooling and extension contact only under improved technology. Factors that promote technology adoption will thus indirectly raise the marginal contributions of farmer education; these include schooling, participatory technology evaluation, improved seed supply, and market access. The results demonstrate that schooling not only enhances agricultural productivity following technology adoption but also promotes adoption itself.  相似文献   
10.
Adoption and impacts of sustainable intensification practices in Ghana   总被引:1,自引:0,他引:1  
Sustainable agricultural intensification requires the use of multiple agricultural technologies in an integrated manner to enhance productivity while conserving the natural resource base. This study analyses the adoption and impacts of sustainable intensification practices (SIPs) using a dataset from Ghana. A multivariate probit (MVP) model was estimated to assess the adoption of multiple SIPs. Moreover, we used a multivalued semi-parametric treatment effect (MVTE) model to estimate the effects of adopting multiple SIPs on maize productivity. The MVP model results show, among others, that access to market, capital, and information/knowledge would enhance the adoption of SIPs. The MVTE model results show that a higher number of SIPs is associated with higher productivity which is more visible when commercial inputs are used in combination with cultural practices. These results have the following policy implications. First, they imply that good rural infrastructure and agricultural services such as rural road network, village-level input delivery system, input credit, and multiple information/knowledge sharing approach (instead of the conventional singular formal information/knowledge sharing approach) can enhance adoption. Second, the results suggest that promoting an integrated use of technologies, instead of a single technology, would have a positive impact on farm productivity and farm household income.  相似文献   
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