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1.
Melinda Smale Joginder Singh Salvatore Di Falco Patricia Zambrano 《The Australian journal of agricultural and resource economics》2008,52(4):419-432
Variety change and genetic diversity are important means of combating crop losses from pests and diseases in modern agricultural systems. Since the Green Revolution, genetic diversity among wheat varieties released in India has increased but variety change on farms continues to be slow. In this article, we define and summarise indices of variety change and genetic diversity for the wheat varieties released and grown in Indian Punjab during the post‐Green Revolution period. We evaluate the effect of each index on technical efficiency with a Cobb‐Douglas yield model after testing for exogeneity. Findings support the hypothesis that slow variety change has offset the positive productivity effects of diversifying the genetic base in wheat breeding during the post‐Green Revolution period. Policies that speed the rate of variety change and contribute to a more equitable spatial distribution of modern varieties could support wheat productivity in the Punjab of India, reinforcing plant breeding successes. 相似文献
2.
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
3.
A multi-sector mathematical programming model of Canadian agriculture (CRAM) is employed to determine the rate of return to yield-increasing research on wheat conducted during 1962–91. The estimated internal rate of return to yield-increasing research ranged between 27% and 31% for the low wheat price scenarios. It was higher at 34–39% for the high wheat price scenarios. Producers captured 80–90% of the benefits. The results support the magnitude of estimated economic benefits reported in previous studies. 相似文献
4.
India's agricultural research spending has long been regionally uneven. Regional research intensity ratios, which account for size differences, indicate research spending has consistently favored southern and western states over northern, central, and eastern ones. Farm production patterns have, however, changed in recent years and regional output growth is being driven by new commodity mixes. In this article, we ask which region had the highest factor productivity growth and rate of return to investments in public agricultural research and higher education. Our analysis relies on a 1980–2008 Indian agricultural production and policy data set together with a dual heteroscedastic production frontier to decompose total factor productivity (TFP) growth into formal technical progress and efficiency elements. The model's regional flexibility affords region‐to‐region comparison of multiple research return rates, TFP growth, and the elements influencing them. Regardless of return‐rate measure or allocation scenario evaluated, the North has enjoyed the highest return to research spending, and the Central and East the lowest. Factor productivity growth has however been strongest in the South, primarily on account of efficiency gains. Overall, though, the technical progress and productivity growth easily attributable to government‐supported research has accounted for about one‐quarter of the sector's TFP growth. 相似文献
5.
Expenditures on agricultural research in the public sector, including the International Agricultural Research Centers (IARCs) have stagnated and in some cases, declined sharply in recent years. This has focused attention on issues of efficiency of agricultural research systems, especially the number, size, scope, type, and locations of their programs. This paper examines the issue of research efficiency through a case study of wheat improvement research in developing countries. The basic premise of this study is that the optimal level of research investment should be determined in a global model that incorporates direct research spill‐ins. An analytical framework is developed to determine the threshold levels of crop production in a country (or a region within a country) needed to justify crop improvement research programs of different sizes in the presence of spill‐ins from abroad. Spill‐in coefficients are estimated from yield performance of varieties of different origins grown across a range of environments. The model is then applied to analyze the efficiency of current investments in 69 wheat improvement research programs in 35 developing countries. A major conclusion of the paper is that given the magnitude of potential spill‐ins from the international research system, many wheat research programs could significantly increase the efficiency of resource use by reducing the size of their wheat research programs and focusing on the screening of varieties developed elsewhere. ©2000 Elsevier Science B.V. All rights reserved. 相似文献
6.
It is widely believed that the Green Revolution had very little effect in unfavourable or marginal environments. Many researchers have been concerned about the slow progress of technical change in marginal environments and the level of research resources allocated to these areas. This paper provides empirical evidence that there has been significant growth in wheat yield potential in marginal environments, especially during the post‐Green Revolution. International yield trial data, covering all major wheat growing environments from 1964 to 1999, were used in estimating the growth in wheat yield potential and changes in yield variability. The global database on wheat varietal adoption and yield gains based on estimated wheat yield growth rates were used to determine production increases due to wheat breeding research. Results show greater progress in shifting the wheat yield frontier in marginal areas, particularly in drought and high temperature environments. Furthermore, yield variability in marginal environments has notably declined, while it has increased slightly in favourable environments. While initial gains came from crossover of varieties from favourable environments, targeted breeding efforts have contributed significantly to more recent productivity growth in marginal environments. Increased production from marginal environments accounted for around 25% of the total wheat production increase in 1997. These findings show greater progress in wheat research and the huge potential of improving wheat productivity in unfavourable environments. 相似文献
7.
D.L. Mather R. Bernsten J.C. Rosas A. Viana Ruano D. Escoto 《Agricultural Economics》2003,29(3):343-352
This paper presents evidence of recent adoption rates of disease resistant bean varieties (RVs), the farm‐level benefits of RV adoption, and the ex post rate of return to disease resistant bean research in Honduras. Results from a farm‐level survey in 2001 in the two principal bean‐producing regions of the country show that 41–46% of bean farmers (depending upon the season) have adopted an RV, and that adoption is neutral with respect to farm‐size and market orientation. An expected utility framework was used to estimate the farm‐level benefits of RV adoption, using a combination of experimental trial and farm‐level survey data. Adopters gain the equivalent of 7–16% (depending on the variety) in bean income from the yield loss averted through RV use. The ex post rate of return to disease resistant bean research in Honduras from 1984 to 2010 is 41.2%. 相似文献
8.
This paper addresses the prospects for technical change in the irrigated rice sector of Senegal, and measures ex‐ante the economic returns to recent research efforts. In 1994, three new rice varieties were released to farmers in the Senegal River Valley (SRV), the major irrigated rice region in Senegal. The productivity advantage of the new varieties is based primarily on early maturity, which permits double‐cropping. (The seeds are also higher yielding than existing cultivars.) We use a conventional [Akino and Hayami (1975), Am. J. Agric. Econ. 57, 1–10] partial‐equilibrium model adapted to the Senegalese situation, to assess the social benefits of research and compare those to its costs in calculating the internal rate of return (IRR). To account for uncertainty regarding the future values of model variables we use simulation which allows us to generate a distribution of all possible outcomes of the IRR. We find that rice research is almost certain to have a very high payoff over the 1995–2004 period. The expected value of the IRR is calculated to be 121% per year, with a 97.5% probability that it lies above annual capital costs of 18%. ©2001 Elsevier Science B.V. All rights reserved. 相似文献
9.
This paper assesses the distributional consequences of technical changes that improve the efficiency of land and of other inputs in a multifactor crop‐production system. We introduced an equilibrium displacement model (EDM) by using the specification of a factor‐augmenting approach. Given the uncertainty about the EDM parameters, a Monte Carlo simulation is used to produce a distribution of possible return measures. We found that land suppliers (likely farmers) receive a larger share (73%) of total benefits from the adoption of land‐technical change than they do from the adoption of other input technologies. Each input supplier receives a larger share of total benefits from technical change in her own input. However, this result is sensitive to the value of the parameters, especially the value of the elasticity of substitution. We applied the EDM to the case of no‐tillage (NT) to provide insight into how the aggregate return from the adoption of NT was distributed among different groups on the Canadian Prairies. The results of this study can be used by policymakers and funding agencies in order to influence landowners and farming communities to adopt environmentally sound land technologies to achieve both greater agricultural productivity and sustainability. 相似文献
10.
Measuring public agricultural research and extension and estimating their impacts on agricultural productivity: new insights from U.S. evidence
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This article provides new estimates of the marginal product of public agricultural research and extension on state agricultural productivity for the U.S., using updated data and definitions, and forecasts of future agricultural productivity growth by state. The underlying rationale for a number of important decisions that underlie the data used in cost‐return estimates for public agricultural research and extension are presented. The parameters of the state productivity model are estimated from a panel of contiguous U.S. 48 states from 1970 to 2004. Public research and extension are shown to be substitutes rather than complements. The econometric model of state agricultural TFP predicts growth rates of TFP for two‐thirds of states that is less than the past trend rate. The results and data indicate a real social rate of return to public investments in agricultural research of 67% and to agricultural extension of 100+%. The article concludes with guidance for TFP analyses in other countries. 相似文献
11.
目的 提高粮食生产效率是保障国家粮食安全的重要任务,对粮食生产中典型的冬小麦—夏玉米复种模式的生产效率进行分析,可以精确把握粮食生产效率,为粮食生产相关政策制定提供参考。方法 文章基于2007—2018年6省(市)面板数据,运用SBM-DEA和Fare-Primont模型从静态和动态视角对冬小麦—夏玉米复种模式的技术效率和全要素生产率的空间分布和时序变动特征进行测算及比较。结果 冬小麦—夏玉米复种模式的平均技术效率和全要素生产率水平值分别为0.793和0.744;机械投入、农药投入和水资源投入的平均冗余率较高,分别为28.693%、26.670%和21.578%。剩余混合效率即投入产出混合比例优化是造成冬小麦—夏玉米全要素生产率地区差异的主要原因;冬小麦—夏玉米复种模式的全要素生产率波动中小幅上升,技术进步、技术效率和剩余混合效率是主要影响因素。结论 冬小麦—夏玉米复种模式的低生产效率客观存在,应通过生产资料的科学合理投入,加快科技创新推广,推动粮食生产适度规模经营等方式来推动粮食高质量发展。 相似文献
12.
C. Thirtle P. Bottomley P. Palladino D. Schimmelpfennig R. Townsend 《Agricultural Economics》1998,19(1-2):127-143
This paper examines the barley and wheat breeding programmes of the Plant Breeding Institute (PBI), which was the most successful public plant breeding institute in the UK, until privatization in 1987. The PBI's shares in barley and wheat seed sales are explained, showing that the success with barley was largely a matter of serendipity, whereas the wheat programme followed a more normal pattern. For wheat, the causal chain, or recursive, model decomposes the well-documented link between research expenditures and increases in agricultural productivity into three stages. These are the effects of R&D expenditures on basic research output, measured by publications, the effect of publications and applied R&D expenditures on trial plot yields, and the diffusion of the trial plot technologies, which raises yields on farms. Applying the model to the FBI's wheat varieties allows estimation of the lag structures. In contrast to the results for aggregate agricultural research, for a single plant breeding programme alone there is a considerable lead time before there is any response, followed by a lag distribution only a few years long. The returns to the R&D investments are calculated from the causal chain model, from single equation estimates and by evaluating the yield advantage of the PBI varieties. All three approaches give consistent results, which show that the returns to barley and wheat alone were sufficient to support the entire PBI budget and still give rates of return to applied research of between 14 and 25%. The return to the basic science expenditures of the John Innes Institute has a lower bound of 17%, but must have been even higher than for the PBI if the other Institutes were taken into account. The paper concludes by commenting on the effects of the privatization of the PBI. 相似文献
13.
José E. Bervejillo Julian M. Alston Kabir P. Tumber 《The Australian journal of agricultural and resource economics》2012,56(4):475-497
We use newly constructed data to model and measure agricultural productivity growth and the returns to public agricultural research conducted in Uruguay over the period 1961–2010. We pay attention specifically to the role of levy‐based funding under INIA, which was established in 1990. Our results indicate that the creation of INIA was associated with a revitalization of funding for agricultural R&D in Uruguay, which spurred sustained growth in agricultural productivity during the past two decades when productivity growth was stagnating in many other countries. The econometric results were somewhat sensitive to specification choices. The preferred model includes two other variables with common trends, a time‐trend variable and a proxy for private research impacts, as well as a variable representing the stock of public agricultural knowledge that entailed a lag distribution with a peak impact at year 24 of the 25‐year lag. It implies a marginal benefit‐cost ratio of 48.2, using a real discount rate of 5 per cent per annum and a modified internal rate of return of 24 per cent per annum. The benefit‐cost ratio varied significantly across models with different lag structures or that omitted the trend or the private research variable, but across the same models, the modified internal rate of return was very stable, ranging from 23 per cent per annum to 27 per cent per annum. These results suggest that the revitalized investment in research spending under INIA has been very profitable for Uruguay and that a greater rate of investment would have been justified. 相似文献
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15.
Conventional estimates of the economic return to agricultural research use market prices for the values of products and inputs; on this basis, economic rates of return are typically well above the cost of capital, suggesting that more investment in research would be socially desirable. But these estimates may be incorrect if, as is often the case, market prices are distorted by market failures or government policies and hence do not reflect social values. This paper presents a simple, partial-equilibrium methodology with which to improve the measurement of social returns to research by taking account of multiple distortions in the market prices of products, inputs and foreign exchange. The method also takes account of variation in domestic and world prices, making a product tradable in some years and nontradable in others. The method is applied to the case of Hageen-Dura 1 (HD-1), Sub-Saharan Africa's first commercially successful hybrid sorghum. HD-1 was released in the Sudan in 1983. From the start of research in 1979 to 1992, the HD-1 breeding program had an estimated IRR of 97% when all major policies in the sorghum market, the fertilizer market, and the exchange rate are taken into account. The high rate of return to HD-1 research was due to the program's low cost and rapid payoff, pointing to the potential value of small adaptive research programs, taking full advantage of foreign technology and genetic material to produce locally-appropriate crosses in a short period of time. Even in the highly distorted economies of Africa, such programs can yield very high payoffs. 相似文献
16.
In 2017, the federal government initiated national consultations for two new crop royalty systems that could be used to support additional crop breeding. In this study, we examine wheat growers’ attitudes towards breeding research and assess their inclination to contribute more to wheat variety development through checkoffs or enhanced royalties. We report a random effect probit estimation for a survey of 877 western Canadian wheat producers that took place from November 2018 to January 2019. We found at least 26% of survey respondents were willing to pay more to support additional wheat breeding. However, this support is contingent on the model for revenue collection and where additional revenue is invested. Producers generally favored increased checkoffs over enhanced royalty collection. Among the royalty options presented, the farm saved seed royalties mechanism had less support than the simpler to implement end-point royalties mechanism. We also found support is much higher if new royalty mechanisms are used to support university or government programs versus private breeding programs. This result suggests developing widespread producer support for enhanced royalty collection may require broader commitments for funding, ownership, and control of crop breeding programs. 相似文献
17.
This paper calculates the rate of return to a set of cowpea research, extension and distribution projects in Senegal to be between 31% and 92%. The results show that a modestly funded program on a secondary crop can be successful. They also indicate that programs may increase their effectiveness by addressing specific household needs – in this case, by focusing on short-cycle varieties that provide food during the hunger season prior to the traditional harvest. 相似文献
18.
The net economic benefits of Canadian federal beef cattle research programs were estimated using the economic surplus approach. The internal rate of return to research expenditure from 1968 to 1984 was found to be 63% at the margin, indicating substantia] underinvestment in technological change. Rates of return indicative of underinvestment were found even when an adjustment was made to research costs to reflect the marginal excess burden of taxation. Most of the benefits of beef cattle research conducted during this time period accrued to Canadian beef producers. Les bénéfices économiques nets des programmes de recherche fédéraux Canadiens sur le boeuf sont estimés en utilisant ?approche du surplus économique. Le taux interne de rendement des défenses de recherche effectuées de 1968 à 1984 est établi à 63%, indiquant un sous-investissement substantiel dans le changement technologique. Même en incluant la perte de bien-être due à ?imposition ?une taxe, ?étude montre un sous-investissement dans la recherche. La plupart des bénéfices de la recherche sur le boeuf effectuée durant cette période ont profité aux producteurs agricoles. 相似文献
19.
In this article, we examine the relationship between public investments in agricultural research and development and the productivity‐enhancing benefits they generate. Knowledge productivity functions are estimated for U.S. agriculture using data on multifactor productivity and public knowledge stocks. We examine the time‐series properties of the data and compare alternative econometric estimation procedures. The results are used to calculate economic performance measures such as internal rates of return and benefit‐cost ratios. The real rate of return to public investments in agricultural research and development in the United States is in the range of 8–10% per annum. 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