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1.
This article quantifies the productivity gain from CIMMYT‐released semidwarf bread wheat (Triticum aestivum) cultivars over time, using test plot data from Mexico's Yaqui Valley. Previous studies have shown a deceleration in irrigated wheat yield growth since the 1980s, which could be due to slowing increase in genetic potential. Our results suggest that CIMMYT cultivars contributed a 0.46% annual increase (about 38 kg/ha annually) to wheat yields in the Yaqui Valley, which raised local wheat producers’ revenue by an average of $4 million annually for the period 1990 to 2002, and by approximately $9 million in 2002. 相似文献
2.
An econometric approach using international and national yield trial data is employed to estimate a spillover matrix for wheat varietal technology. The global spillover matrix is estimated based on international yield trial data from 1979–80 to 1987–88, that include 195 international trial locations and 209 wheat varieties. The locations were classified across countries using the CIMMYT's wheat megaenvironment system and varieties were classified by both their environmental and institutional origin. The model gave good explanatory power and confirmed the location specificity hypothesis, at least, for the varieties developed by national programs (NARS). The spillover matrix shows that NARS varieties developed in the home' environment generally perform better on average than varieties developed in other megaenvironments. Also, the matrix is not symmetric. CIMMYT varieties perform better on average in irrigated and high rainfall environments than NARS varieties developed for these environments. The yield advantage of CIMMYT varieties in many test megaenvironments indicates the potential of CIMMYT varieties to spill-over to these test megaenvironments. Results also indicate that national programs are efficient in selecting from among imported technologies. Analysis of international data is complemented by the analysis of country-level data for Pakistan and Kenya that confirms the above results. The country-level analysis, however, indicates that CIMMYT germplasm does not do so well in some sub-environments, such as the irrigated short-duration environment. The results of the spillover matrix have implications for the design of crop breeding programs both at the national and international levels. Information provided by the spillover matrix can be utilized by national programs to deploy their resources more efficiently by following a mixed strategy of direct importation of technology in some environments and local development of technologies in other environments which are unique to the country. 相似文献
3.
Wheat genetic materials developed from research at the International Maize and Wheat Improvement Center (CIMMYT) in Mexico for developing countries have provided spillover benefits to Australia. Varieties developed from those genetic materials have resulted in yield increases in Australia. While the initial impact came through the introduction of higher-yielding semi-dwarf wheat crops, those impacts have continued in the post-semidwarf period. CIMMYT's success in developing countries has also reduced the world price for wheat. While the lower prices affect returns in Australia, the increased yields in Australia from the CIMMYT spillovers from both the semi-dwarfs and the post-semidwarf phases have provided benefits to Australia averaging A$30 million per year. 相似文献
4.
This paper reports the results of a study undertaken to estimate the economic impact in developing countries of efforts by the International Maize and Wheat Improvement Center (CIMMYT) to breed leaf rust resistant spring bread wheat varieties since 1973. The challenge in estimating these benefits lies in the pathogen's ability to mutate to new races, which may infect previously resistant varieties. Genetic resistance, rather than fungicide application, is the principal means of controlling leaf rust in developing countries. Whereas productivity enhancement is often estimated in terms of yield gains and increased supply, productivity maintenance is measured in terms of the yield losses avoided by the research investment. The internal rate of return on CIMMYT's research investment was estimated at 41%. When discounted by 5%, the net present value was US$ 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
5.
An analysis of the annual costs of weeds in seven winter crops across Australia demonstrated that the most important 15 weed species cause substantial annual costs in both financial and economic terms. Using survey data captured over the 1998–1999 growing season, the financial cost of these weeds in seven crops was estimated to be AU$1,182 million. The main components of this cost were herbicides (AU$571 million), the competitive effects of residual weeds (AU$380 million), and tillage (AU$206 million) while weed contamination of grain was a minor cost (AU$25 million). Across all regions, the most economically important weeds were annual ryegrass, wild oats, and wild radish, although there were regional differences in importance. An economic surplus analysis determined the annual economic cost of weeds in annual winter crops to be AU$1,279 million. This surplus loss represented 17% of the gross value of Australian grain and oilseed production in 1998–1999. Australian grain producers incurred a major loss, with a reduction in producer surplus of AU$1,047 million. Australian grain consumers had a large consumer surplus loss (AU$229 million), while international consumers suffered a small loss and international grain producers gained a small producer surplus from the higher grain prices. 相似文献
6.
The widespread commitment of public funds to agricultural research is being questioned by administrators in governments and by the Canadian public. Questions relating to the level of public expenditure on agricultural research, the efficiency with which the resources are being allocated, and the manner in which the benefits are distributed among members of society art being asked. This study addresses these and related questions as they pertain to publicly funded wheat research activities conducted over the period 1946 to 1979- Two research scenarios were examined - one dealing with the development of new varieties of wheat and the other dealing with all research applicable to the production of wheat. The results revealed that society has indeed benefitted substantially from public investment in wheat research. The level of social benefits averaged $49 and $143 million (measured in 1971 dollars) annually for the wheat breeding and all-wheat research scenarios, respectively. The average annual internal rates of return earned from these public investments ranged between 30 and 39 percent. Furthermore, some evidence was presented that suggests society may, in fact, be underin-vesting in agricultural research in the aggregate. Finally, analyses of the distribution of the benefits showed that both producers and consumers are major beneficiaries. 相似文献
7.
Ex Ante Welfare Analysis of Technological Change: The Case of Nitrogen Efficient Maize for African Soils
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This study evaluates the potential impacts of the Improved Maize for African Soils (IMAS) project in two countries of Africa: Kenya and South Africa. The IMAS varieties offer significant yield advantages for regions where low or no fertilizer is used. The analysis uses spatial production data and household data to account for the level of fertilizer use in different agroecological zones of the country as well as different types of maize producing households. Results suggest that IMAS will deliver a total of US$586 million in gross benefits with US$136 million and US$100 million of benefits to producers in Kenya and South Africa, respectively, and an additional US$112 million to consumers in Kenya and US$238 million to consumers in South Africa. These benefits could help more than 1 million people escape poverty in the two countries by 2025. Household level results suggest that small households in areas with relatively low levels of fertilizer use stand to gain significant benefits. 相似文献
8.
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
9.
David T. Vere Randall E. Jones Garry R. Griffith 《The Australian journal of agricultural and resource economics》2003,47(4):519-539
The present paper reports an economic evaluation of the long-term benefits to Australia of research by the Cooperative Research Centre for Weed Management Systems (CRC) into the improved management of vulpia , the major annual grass weed of temperate pastures in New South Wales and Victoria. Vulpia reduces livestock production by competition with more desirable pasture species, by the production of low quality feed at critical times of the grazing cycle, and by injury to animals. A 20-year stochastic benefit-cost analysis indicated that reducing the impacts of vulpia in these pastures produced a mean net present value of $A58.3 million and a mean benefit-cost ratio of 33:1. Temperate pasture zone wool producers would capture the largest shares of these benefits, Australian consumers would gain, but wool producers in the rest of Australia would suffer welfare losses from vulpia reductions in the temperate pasture zones. 相似文献
10.
Returns to investment in wheat breeding research in Nepal were estimated for two periods: (1) the Green Revolution period (1960–1990), when modern semidwarf wheat varieties first appeared and spread throughout the country, and (2) the post-Green Revolution period (after 1990), when first-generation modern varieties will be replaced by newer materials. Major benefits of the Nepalese wheat breeding program have included maintenance of disease resistance and faster dissemination of exotic germplasm. Attractive rates of return to investment in wheat breeding have been due in part to Nepal's ability to capture spillover benefits from neighboring countries and from international agricultural research centers. 相似文献
11.
In recent years, the wheat sector in Brazil has moved from governmental protection and public intervention to a free market and privatization. In this study, those changes are analyzed through measures of governmental intervention on nominal rates of protection and on welfare of producers and consumers. Elasticities of demand and supply of wheat are estimated, and the effects of changes in policies are analyzed under official and shadow exchange rates. Welfare measures indicate that almost US$ 8 billion were spent from 1970 until 1989 with policies to subsidize producers and consumers. The policy-induced stimulus to consumer demand exceeded the stimulus to domestic production, and self sufficiency in wheat declined. The reduction in wheat subsidies since 1989 was more than an isolated sector-specific policy. It was part of macroeconomic antiinflation policy, and it coincided with other economy-wide changes such as real appreciation and a decline in international commodity prices. 相似文献
12.
We derive a method to econometrically estimate the tariff equivalent and forgone trade effects of a prohibitive technical barrier to trade (TBT) based on Wales and Woodland's Kuhn–Tucker approach to corner solutions in consumer choice. The method overcomes the lack of observed data on bilateral trade flows and accounts for differentiated goods by place of origin. We apply the derived random utility model to international trade in apples to identify the tariff equivalent of prohibitive phytosanitary barriers imposed by Australia on potential imports of New Zealand apples. We estimate the forgone apple trade between the two countries, the implied trade injury imposed by Australia on New Zealand, and the welfare loss to Australia. The removal of the Australian policy would induce net welfare gains around US$50 million annually for Australia. 相似文献
13.
Models are constructed to assess the welfare effects for producers, consumers and society of producers using forecast prices based on more accurate estimates of variables causing shifts in the demand for and supply of commodities. The basic model is a stochastic cobweb model in which producers' forecast price is the rational forecast price. The model is extended for many commodities, for partial producer response to more accurate forecast prices, and to include stock holding. In terms of economic surplus, producers and consumers gain from more accurate estimates of demand shift variables, producers gain and consumers lose from more accurate estimates of supply shift variables, and in both cases there is a net society gain. 相似文献
14.
Gokul P. Paudel Vijesh V. Krishna Andrew J. McDonald 《Journal of Agricultural Economics》2020,71(1):199-218
The ‘high speed’ rotavator is used for shallow tillage to create a fine tilth and incorporate crop residues, often with a single tractor pass. Rotavator tillage has spread quickly in many parts of South Asia, despite short-term experimental trials suggesting deteriorating soil quality and crop yield penalties. Evidence of rotavator impacts on farmer fields across soil gradients and time is largely absent. From a farm household survey conducted among wheat farmers in Nepal, we estimate wheat yield and profitability outcomes for rotavator adopters and non-adopters using propensity score matching. We find that rotavator adoption leads to inferior outcomes, despite significant cost savings for land preparation (US$ 11–15 per hectare). With rotavator adoption, farmers lose about 284–309 kg of wheat grain and about US$ 93–101 of profits on average per hectare per season, and these penalties increase with longer-term use of the technology. Adoption of rotavator appears to be driven by the cost and time savings for land preparation. Against this backdrop, new policy and extension efforts are required that discourage rotavator use and favour more sustainable tillage technologies. 相似文献
15.
Adam M. Komarek James Thurlow Jawoo Koo Alessandro De Pinto 《Agricultural Economics》2019,50(6):765-778
Climate‐smart agriculture (CSA) is an approach for transforming and reorienting agricultural systems to support food security under climate change. Few studies, however, quantify at the national scale CSA's economic effects or compare CSA to input‐intensive technologies, like fertilizer or irrigation. Such quantification may help with priority setting among competing agricultural investment options. Our study uses an integrated biophysical and economic modeling approach to quantify and contrast the economywide effects of CSA (integrated soil fertility management in our study) and input‐intensive technologies in Ethiopia's cereal systems. We simulate impacts for 20‐year sequences of variable weather, with and without climate change. Results indicate that adopting CSA on 25% of Ethiopia's maize and wheat land increases annual gross domestic product (GDP) by an average 0.18% (US$49.8 million) and reduces the national poverty rate by 0.15 percentage points (112,100 people). CSA is more effective than doubling fertilizer use on the same area, which increases GDP by US$33.0 million and assists 75,300 people out of poverty. CSA and fertilizer have some substitutability, but CSA and irrigation appear complementary. Although not a panacea for food security concerns, greater adoption of CSA in Ethiopia could deliver economic gains but would need substantial tailoring to farmer‐specific contexts. 相似文献
16.
Genti Kostandini Bradford F. Mills Steven Were Omamo Stanley Wood 《Agricultural Economics》2009,40(4):477-492
This article develops a framework to examine the ex ante benefits of transgenic research on drought in eight low-income countries, including the benefits to producers and consumers from farm income stabilization and the potential magnitude of private sector profits from intellectual property rights (IPRs). The framework employs country-specific agroecological–drought risk zones and considers both yield increases and yield variance reductions when estimating producer and consumer benefits from research. Benefits from yield variance reductions are shown to be an important component of aggregate drought research benefits, representing 40% of total benefits across the eight countries. Further, estimated annual benefits of US$178 million to the private sector suggest that significant incentives exist for participation in transgenic drought tolerance research. 相似文献
17.
Measuring Farm and Market Level Economic Impacts of Improved Maize Production Technologies in Ethiopia: Evidence from Panel Data 总被引:1,自引:0,他引:1
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Menale Kassie Paswel Marenya Yohannis Tessema Moti Jaleta Di Zeng Olaf Erenstein Dil Rahut 《Journal of Agricultural Economics》2018,69(1):76-95
While it is often recognised that agricultural technology adoption decisions are intertwined and best characterised by multivariate models, typical approaches to examining adoption and impacts of agricultural technology have focused on single technology adoption choice and ignored interdependence among technologies. We examine farm‐ and market‐level impacts of multiple technology adoption choices using comprehensive household survey data collected in 2010/11 and 2012/13 in Ethiopia. Economic surplus analysis combined with panel data switching endogenous regression models are used to compute the supply shift parameter (K‐shift parameter), while at the same time controlling for the endogeneity inherent in agricultural technology adoption among farmers. We find that our improved technology set choices have significant impacts on farm‐level maize yield and maize production costs, where the greatest effect appears to be generated when various technologies are combined. The change in maize yield and production costs results in an average 26.4% cost reduction per kilogram of maize output (the K‐shift parameter). This increases the producer and consumer surpluses by US$ 140 and US$ 105 million per annum, respectively. These changes in economic surplus help to reduce the number of poor people by an estimated 788 thousand per year. We conclude that deliberate extension efforts and other policies that encourage integration of technologies are important for maize technologies to yield their full potential at both farm and market levels. 相似文献
18.
Peter Tozer Thomas L. Marsh 《The Australian journal of agricultural and resource economics》2012,56(3):385-404
Australia is the sixth largest producer of beef and the second largest exporter of beef. Average beef exports from Australia are approximately 65 per cent of the total amount of beef produced, about 1.3 million tonnes. Australia is particularly vulnerable to diseases that are not endemic to the country and could close or disrupt its export markets for beef. In this study, we construct a bioeconomic optimisation model of the Australian beef industry that captures production and consumption decisions, domestically and internationally, and the impacts on the beef industry of a potentially catastrophic disease, foot‐and‐mouth disease (FMD). This study analyses localised to large‐scale outbreaks and suggests that changes in economic surplus because of FMD range from a positive net gain of $57 million to a net loss of $1.7 billion, with impacts on producers and consumers varying depending on the location of the outbreak, control levels and the nature of any trade ban. 相似文献
19.
The distribution of welfare gains of genetic improvements in major US crops is estimated using a world agricultural trade model. Multi-market welfare estimates were 75% larger than estimates based on the price-exogenous 'change in revenue' method frequently used by plant breeders. Annual benefits of these genetic improvements range from US$ 400–600 million depending on the supply shift specification. Of this, 44–60% accrues to the US, 24–34% accrues to other developed countries. Developing and transitional economies capture 16–22% of the welfare gain. The global benefits of a one-time permanent increase in US yields are US$ 8.1 billion (discounted at 10%) and US$ 15.4 billion (discounted at 5%). Gains to consumers in developing and transitional economies range from US$ 6.1 billion (10% discount rate) to US$ 11.6 billion (5% discount rate). 相似文献
20.
文章通过对西北5省2000~2013年小麦生产情况、小麦高产创建取得的效益综合分析,结果显示:西北5省小麦种植面积持续下降,单产稳步提升,高产创建万亩片的效益远高于西北5省的平均单产。推广综合集成技术和加大投入是增产的关键,西北5省区小麦生产仍有很大的挖掘潜力。今后挖掘西北5省小麦增产潜力要依靠科学技术,加大优良新品种选育,建全新优品种的推广力度,改善农田基础设施,提高耕地产出能力,促进土地承包经营,推动生产全程机械化,持续加大投入,加强灾害预警与抗逆减灾技术研发,科学抗灾减损。提出要将高产田的种植技术推广应用到大田生产中,实现在现有种植面积不扩大的前提下,产量大幅度提高。为实现口粮绝对安全,需要进一步稳定供给,在挖掘科技潜力,扩大推广展示引导的基础上,探索多渠道的动态补贴机制,保障种粮主体的积极性。 相似文献