共查询到20条相似文献，搜索用时 15 毫秒
1.
Although adoption rates of genetically modified crops have been staggering in some countries, there is still comparatively little evidence about biotechnology impacts under diverse agroecological and institutional conditions. These knowledge gaps lead to an overly precautious attitude among policy makers and the public. This article analyzes the effects of Roundup Ready (RR) soybeans in Argentina, the country with the second biggest transgenic area worldwide. Based on recent survey data, it is shown that the technology increases total factor productivity by 10% on average, with cost savings being somewhat more pronounced for smaller than for larger farms. The reduction in use of toxic herbicides and of tillage operations entails positive environmental repercussions. Aggregate welfare effects are computed over the 1996–2001 period with a three-region, partial equilibrium model, comprising Argentina, the United States, and the rest of the world. In 2001, RR soybeans created more than US$1.2 billion of economic surplus at the global level. The largest share went to consumers (53%), followed by seed and biotechnology firms (34%), and agricultural producers (13%). Due to comparatively weak intellectual property protection, and thus only small technology mark-ups in seed prices and widespread adoption, Argentine soybean growers receive 90% of the benefits in that country. This demonstrates that farmers in developing countries can gain considerably when they obtain access to suitable foreign innovations through technology spill-overs. 相似文献
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A.S. Langyintuo G. Ntoukam L. Murdock J. Lowenberg-DeBoer D.J. Miller 《Agricultural Economics》2004,30(3):203-213
Consumer preference information is essential to targeting research. This paper reports an effort of a multi‐disciplinary team to measure the market value of cowpea characteristics. Five samples were purchased once per month in seven markets in Ghana and Cameroon starting in September 1996. In the market, price and vendor characteristics were noted. In the laboratory, size of grains, testa color, testa texture, eye color and damage levels were recorded. A hedonic pricing regression model was used. Results indicate that grain size is the most important characteristic. Consumers seem more sensitive to bruchid (Callosobruchus maculates) damage than hypothesized. Cowpeas with white testa command a clear premium only in one of the Ghanaian markets. In Ghana, black eyes sell at a premium, but in Cameroon black eyes are discounted. In general, this study indicates that quality characteristics are very important in West African food markets. Even low income consumers are willing to pay a premium for products that match their preferences, and they are vigilant in identifying products that do not meet their standards. Purchasing samples on a regular basis and hedonic pricing offers a practical way for biological scientists and economists to work together to measure these consumer preferences. 相似文献
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Although recurrent evidence is found that consumers have different willingness to pay for GM and non-GM products, there is disagreement in the scientific community about the size of consumer benefits from GM labeling. In this article we use a theoretical model based on a standard constant elasticity of substitution (CES) to explain the importance of the quality effect. It is shown that failing to consider the quality effect may yield an overestimation of benefits from GM labeling, voluntary or mandatory. 相似文献
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We analyze sources of information in agricultural markets to understand patterns of demand for decision support services and the division of labor in the supply of these services. Information formatting—qualitative variation that determines accessibility and relevance of information in specific contexts—prohibits universal access to informational content. Information formats give rise to both transaction costs and complementarities reflected in patterns of information exchange in commodity systems. Controlling for actors' structural roles and levels of education, we develop a hedonic model of information demand such that actors seek information that is formatted to meet their needs and capabilities. Employing survey data, we explain elements of observed patterns of information exchange in four commodity systems in the USA. Results point to opportunities to expand our understanding of socioeconomic processes underlying production and consumption of decision support. 相似文献
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Investments in agricultural research and development (R&D) made over the next few decades will likely prove critical in offsetting adverse climate change impacts on the global food system. In this study, we offer cost estimates of public R&D-led adaptation to climate change grounded in an explicit framework relating the flow of annual R&D expenditures to building knowledge capital and thereby raising productivity in agriculture. Our research uses a comprehensive collection of historical public agricultural R&D expenditure and a literature review of elasticity estimates linking knowledge stocks to agricultural productivity growth for key world regions. Given climate-driven crop yield projections generated from extreme combinations of crop and global circulation models, we find that offsetting crop yield losses projected by climate and crop models over 2006–2050 would require increased R&D adaptation investments of between $187 billion and $1,384 billion (in 2005 $PPP) if we invest between 2020 and 2040. This is 16–118% higher than global R&D investment if present spending trends continue. Although these costs are significant, worldwide R&D-led climate adaptation could offer favorable economic returns. Moreover, R&D-led adaptation could deliver gains in food security and environmental sustainability by mitigating food price increases and slowing cropland expansion. 相似文献
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Pepijn Schreinemachers Teresa Sequeros Philipo Joseph Lukumay 《Agricultural Economics》2017,48(6):707-717
There is a lack of evidence for impact at scale of vegetable research and development, although the importance of vegetables for human nutrition and smallholder incomes is generally understood. We therefore study adoption and impact of improved tomato and African eggplant varieties developed through international agricultural research, released by national agricultural research and extension systems, and supplied to farmers by private seed companies in East and Southern Africa from 1990 to 2014. The study finds that in 2014, varieties developed by the World Vegetable Center accounted for 50% of tomato and 98% of African eggplant commercial seed production in East and Southern Africa. For Tanzania alone, investment in crop improvement generated economic gains of US$ 255 million for tomato and US$ 5 million for African eggplant up to 2014. The internal rate of return is 26% for tomato and 12% for African eggplant, though we project the latter to increase to 26% by 2024 as the variety was released only in 2007. These findings support the view that agricultural policy and investment reoriented towards contemporary nutritional challenges will give high returns to investment. 相似文献
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Edward Oczkowski 《Agricultural Economics》2006,34(1):97-107
This article presents an econometric model of winegrape prices which recognizes the existence of demand and supply imbalances in the Australian market. A “markets in disequilibrium” framework is employed to motivate modeling price changes as responding to variations in excess demand/supply. The disequilibrium price equation provides estimates of regional and varietal price discounts/premiums and a measure of the speed of disequilibrium price adjustment. The equilibrium assumption is rejected for the market and substantial differences between equilibrium and disequilibrium estimates point to the inaccuracies of assuming market clearing. Disequilibrium estimates point to significant differences between warm and cool regions and changing speed of disequilibrium adjustment over time. 相似文献
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Robert J. Farquharson Oscar J. Cacho John D. Mullen Graeme D. Schwenke 《Agricultural Economics》2008,38(2):181-192
Soil fertility decline and soil management for crop production are important economic issues for grain growers in north-eastern Australia. In that region, there is evidence of soil fertility decline which is attributed to past crop management practices. The questions addressed in this article are first, whether components of soil fertility can be improved by better management and second, by how much soil fertility would change. Soil fertility for crop production is considered in terms of soil organic carbon and nitrogen. A stochastic dynamic economic analysis of soil fertility management for wheat production is presented. A sequential analysis of first deriving the optimal nitrogen stock and application rates is followed by an assessment of tillage, stubble, and fertilizer strategies to obtain an optimal level of soil organic carbon. The recommended management practices are consistent with emerging management trends in the region. The derivation of optimal levels of soil fertility for agricultural purposes has other policy implications, which we discuss. 相似文献
10.
The Lore Lindu region in Indonesia—as in many forest frontier areas in Southeast Asia—has experienced rapid deforestation due to agricultural expansion in the uplands, at the forest margins. This has resulted in aggravated problems of erosion and water availability, threatening agricultural productivity growth. At the same time, technical progress is promoting agricultural intensification in the lowlands. In this article, we examine how improved technologies for paddy rice cultivation in the lowlands have affected agricultural expansion and deforestation in the uplands. The question of a “forest‐saving” or “forest‐clearing” effect related to technical innovation is important from a sustainable development perspective and remains a controversial issue in the literature. We address this question for the Lore Lindu region with an empirical model in which expansion in the lowlands and the uplands is estimated simultaneously. We use data from an extensive village survey conducted in the region, combined with GIS data. To guide the empirical analysis, we develop a theoretical framework based on a Chayanov‐type agricultural household model. The model analyzes farmers' land allocation decisions, taking into account the lowland–upland dichotomy in the agricultural sector. The empirical findings, corroborated by the analytically derived results, show how technical progress for lowland production affects land use at the forest margins and how these effects depend on the factor‐intensity of the technology. The findings imply specific rural development policies for sustainable agricultural intensification in forest frontier areas. 相似文献
11.
Emilio Galdeano 《Agricultural Economics》2005,33(2):163-177
This article analyzes consumer preference for fruit and vegetables when, by using time series with socioeconomic characteristics of households, there can be seemingly unobserved quality effects, which are increased by aggregation. The changes in Spanish demand for fresh and processed fruit and vegetables over the period 1987–2000 are discussed. Following previous tests and analyses, quantities are taken as predetermined and prices as matching the offer conditions. Thus, quality effects (based on the nutritional and/or health value of the product) are estimated from the error terms associated with the functions of the unit values. Quality variables are introduced as taste shifters in the inverse demand system (Laitinen–Theil model). The results show the positive effects of quality differences on the normalized price for the group of products through own‐quality flexibilities, and the negative effects between fresh and processed products through cross‐quality flexibilities. 相似文献
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Many investment decisions of agribusiness firms, such as when to invest in an emerging market or whether to expand the capacity of the firm, involve irreversible investment and uncertainty about demand, cost or competition. This paper uses an option‐value model to examine the factors affecting an agribusiness firm's decision whether and how much to invest in an emerging market under demand uncertainty. Demand uncertainty and irreversibility of investment make investment less desirable than the net present value (NPV) rule indicates. The inactive firm is more reluctant to enter the market when it takes into account demand uncertainty because it preserves the opportunity of making a better investment later. The active firm is more reluctant to abandon the investment because there is an option value of keeping the operation alive. There is a greater distance between the entry and exit thresholds under the option‐value approach than under the NPV rule due to demand uncertainty. The results have implications for agribusiness decision‐making. 相似文献
13.
Lewis T. Cunningham III B. Wade Brorsen Kim B. Anderson Emílio Tostão 《Agricultural Economics》2008,38(1):1-7
Recent research has found that men trade stocks more frequently than women and receive a lower price as a result. The behavioral finance literature attributes this greater trading activity to men's overconfidence. Women's lack of overconfidence and past agricultural economics research suggest the possibility that women may be better at marketing grain than men. This article uses actual transactions of farmers marketing wheat and also finds that men trade more often than women. Women also sell two weeks later in the marketing year. There is no direct effect of gender on price received, but by storing longer women receive 1.4 cents/bushel less than men, on average. In contrast to the arguments in previous research, we argue that men's greater number of trades can be better explained by men enjoying trading rather than by overconfidence. 相似文献
14.
Risk and uncertainty have often been suggested as causes of poor adoption of rural innovations, but empirical evidence has been scarce. This study focuses on a new crop‐type, chickpeas, in Western Australia to gather such evidence. The empirical models developed are based on a theoretical framework that conceptualizes adoption as a dynamic decision process involving information acquisition and learning‐by‐doing by growers who vary in their managerial abilities, risk preferences, and their perceptions of the profitability and riskiness of the innovation. Learning encompasses improvements in skill as well as reductions in uncertainty. An annual face‐to‐face survey of over 100 farmers was conducted over 3 years, eliciting the farmers' risk attitudes and their subjective distributions of yields and prices. Two limited dependent variable models, Tobit and Probit, are used to estimate the empirical model. There is a high degree of goodness‐of‐fit for both models. The study provides strong empirical support for the primarily economic character of the adoption decision, and highlight the importance of economic risk in the process. The two risk‐related factors with greatest impact on the adoption decision were risk aversion and relative riskiness of the innovation. Risk aversion tended to reduce adoption, and to do so to a greater extent as relative riskiness and scale increased. Results also reveal the key role that trialing of the innovation plays in adoption. 相似文献
15.
We estimate a food demand system in Paraguay based on the 1997 national household survey, considering 12 food categories. To obtain demand elasticity estimates from household survey data accounting for quality effects, measurement errors, and censored observations, price indexes are obtained from ordinary least squares predictions of changes in unitary values caused by spatial and temporal variations, and the two‐step estimation procedure ( Shonkwiler and Yen, 1999 ) is applied. Our approach yields reasonable estimates of combined quantity and quality responses with respect to price. Results suggest distinct consumption behavior in urban and rural areas, particularly for chicken, eggs, dairy, and fats and oils, which are likely because of differences in the food distribution system and availability of nonmarket food sources. 相似文献
16.
A rational expectations competitive storage model was applied to the U.S. corn market, to assess the aptness of this framework in explaining monthly price behavior in an actual commodity market. Relative to previous models, extensive realism was added to the model, in terms of how production activities and storage costs are specified. By modeling convenience yield, “backwardation” in prices between crop years did not depend on the unrealistic assumption of zero ending stocks. Our model generated cash prices that were distributed with positive skewness and kurtosis, and mean and variance that increased over the storage season, comparable to the persistence and the occasional spikes observed in commodity prices. Futures prices were generated as conditional expectations of cash prices at contract maturity, and the variances of futures prices exhibited realistic time–to‐maturity and seasonal patterns. Model realizations of cash and futures prices over many “years” were used to demonstrate the wide variety of price behaviors that could be observed in an efficient market with a similar market structure, implying that economic and policy implications drawn from short, historical samples of prices could be misleading. 相似文献
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We estimate a CBS system model of U.S. derived demand for meat. We use this model (1) to examine relationships between three quality categories of beef and three other meats and (2) to simulate how taste shifts have affected demands for meats over time. We extend previous studies by disaggregating wholesale beef production into three quality categories: (1) USDA Choice grade or higher, (2) USDA Select or lower, and (3) cow and bull beef. Innovative features of our empirical model include a breakout of ‘table cuts’ into Choice and Select and the use of a hedonic characterization of the two breakouts to value “Choice‐ness” and “beef‐ness.” Our model demonstrates important shifts in separate demands for Choice and Select beef. We show that, separately, the demand for Choice‐grade beef declined in the 1980s and 1990s and the demand for Select beef increased, a departure from the relatively stable demand characterizations of more aggregated measures of combined Choice and Select beef. 相似文献
20.
Frank Asche Atle G. Guttormsen Tom Sebulonsen Elin H. Sissener 《Agricultural Economics》2005,33(3):333-340
This article examines the Japanese market for salmon. This market is of interest, since it is the largest and most diversified salmon market in the world with wild and farmed species, from Europe and South and North America, competing in the same market. In contrast to the European Union (EU)‐ and U.S.‐markets, there have been neither trade conflicts nor trade restrictions. The Japanese market can hence provide information about the impact of bringing substantial quantities of a new product into a market, and the effect of large‐scale aquaculture on traditional fisheries. In this article, market integration between wild and farmed salmon on the Japanese market is examined, using both bivariate and multivariate cointegration analysis. Tests for the Law of One Price are also conducted. The results indicate that the species are close substitutes on the market, and that the expansion of farmed salmon has resulted in price decreases for all salmon species. 相似文献