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1.
In the continuing debate over the impact of genetically modified (GM) crops on farmers of developing countries, it is important to accurately measure magnitudes such as farm‐level yield gains from GM crop adoption. Yet most farm‐level studies in the literature do not control for farmer self‐selection, a potentially important source of bias in such estimates. We use farm‐level panel data from Indian cotton farmers to investigate the yield effect of GM insect‐resistant cotton. We explicitly take into account the fact that the choice of crop variety is an endogenous variable which might lead to bias from self‐selection. A production function is estimated using a fixed‐effects model to control for selection bias. Our results show that efficient farmers adopt Bacillus thuringiensis (Bt) cotton at a higher rate than their less efficient peers. This suggests that cross‐sectional estimates of the yield effect of Bt cotton, which do not control for self‐selection effects, are likely to be biased upwards. However, after controlling for selection bias, we still find that there is a significant positive yield effect from adoption of Bt cotton that more than offsets the additional cost of Bt seed.  相似文献   

2.
Granivorous birds, mainly the Red‐billed Quelea, have subsisted on cereal crops in Africa for centuries and have caused substantial damage. There is, however, limited recent evidence on their impact. We propose an indirect method to estimate bird‐inflicted crop losses by fitting a production function with a damage abatement component and pest intensity slope dummies on a panel database of rice farmers in the Senegal River Valley. This allows us to estimate both bird damage and marginal productivity of bird control at different levels of bird pressure. Annual bird damage is found to average around 13.2% of the potential rice production during the wet seasons of 2003–2007, which translates into an average annual economic loss of 4.7 billion FCFA (€7.1 million). Our results are consistent with farmers’ perceived bird‐inflicted crop losses, averaging 15.2%. More alarmingly, we observe declining marginal productivities of bird control under increasing bird pressure. Farmers indicate that at high bird pressure, the efficacy of traditional bird scaring methods is inadequate, which suggests that predictive (monitoring), preventive (population control) and protective (insurance) measures against massive invasions are more urgent than improving the average efficacy of curative measures (pest control). These findings are especially relevant to farmers and policy‐makers who are currently struggling to implement an ambitious food self‐sufficiency programme in Senegal.  相似文献   

3.
While much effort has been devoted to estimating market premiums for non‐genetically modified (GM) food, the results of such research are largely silent about the preferences for the public good aspects, or externalities, of GM food production. For public goods, the closest substitute of private consumption decisions is voting on referenda. In November 2005, 55.7% of 2 million Swiss voters approved a five‐year moratorium (ban) on the commercial cultivation of GM plants in Switzerland. The present study examines how individual voting decisions were determined by: (i) socioeconomic characteristics; (ii) political preference/ideology; and (iii) agreement with a series of arguments in favour and against the use of GM plants in Swiss agriculture. The analysis is based on the data of the regular voter survey undertaken after the national‐level voting in Switzerland. The results suggest that current concerns about the use of genetically engineered plants in agriculture may not automatically decrease with higher levels of education/knowledge and generational change. Furthermore, analysis of voter motives suggests that public support for a ban on GM crops may be even larger in other countries, where industrial interests in crop biotechnology are less pronounced.  相似文献   

4.
How much might the potential economic benefit from enhanced farm productivity associated with crop biotechnology adoption by Australia and New Zealand (ANZ) be offset by a loss of market access abroad for crops that may contain genetically modified (GM) organisms? This paper uses the Global Trade Analysis Project (GTAP) model to estimate effects of other countries' GM policies without and with ANZ farmers adopting GM varieties of various grains and oilseeds. The gross economic benefits to ANZ from adopting GM crops under a variety of scenarios could be positive even if the strict controls on imports from GM‐adopting countries by the European Union are maintained, but not if North‐East Asia also applied such trade restaints. From those gross economic effects would need to be subtracted society's evaluation of any new food safety concerns and negative environmental externalities (net of any new environmental and occupational health benefits), as well as any extra costs of segregation, identity preservation and consumer search.  相似文献   

5.
The potential contributions of new biotechnologies to sustainable food and income security have been the subject of widespread discussions around the turn of the 21st century. But distributional issues of which segments of adopters of genetically modified (GM) crops benefit the most have not been given ample attention). Using propensity scores, we apply the (a) stratification‐multilevel method of estimating heterogeneous treatment effects; and the (b) matching‐smoothing method of estimating heterogeneous treatment effects proposed by Xie et al. We find that the incidence of higher yields, lower insecticide use, and reduced seed utilization in the Philippines diminishes progressively as a farmer's propensity to adopt Bt corn increases. Farmers with a low propensity to adopt Bt are those who farm smaller, nonirrigated farms located farther from seed suppliers and farmers without previous training on pest identification. In most cases, while these farmers are typically poorer farmers in smaller parcels, cannot afford irrigation and are situated in remote areas away from easily accessible seed suppliers, there is no evidence, however, that profits differ across farmers with varying propensities to adopt the Bt variety.  相似文献   

6.
The impact of social networks on hybrid seed adoption in India   总被引:4,自引:0,他引:4  
This article adds to the literature about the impact of social networks on the adoption of modern seed technologies among smallholder farmers in developing countries. The analysis centers on the adoption of hybrid wheat and hybrid pearl millet in India. In the local context, both crops are cultivated mainly on a subsistence basis, and they provide examples of hybrid technologies at very different diffusion stages: while hybrid wheat was commercialized in India only in 2001, hybrid pearl millet was launched in 1965. The analysis is based on surveys of wheat and millet farmers in the state of Maharashtra. Comprehensive data on farmer characteristics and social interactions allow for identifying individual networks, thereby improving upon previous research approaches that employed village-level variables as proxies for network effects. Using econometric models, we find that individual social networks play an important role for technology adoption decisions. While village-level variables may be used as suitable proxies at later diffusion stages, they tend to underestimate the role of individual networks during early phases of adoption.  相似文献   

7.
Farmers in low‐income rural economies often fail to switch to cash crops from staple production despite the positive income effects of commercialization expected by policy makers. The literature suggests that market failures prevent households from cash crop adoption but remains inconclusive regarding farmers' motives and the effects of commercialization. This article contributes to the debate by offering an original approach to the analysis of commercialization outcomes and farmers' decisions. It consists of applying a model with essential heterogeneity and a semiparametric estimation technique to analyzing harvest value returns to cash cropping. Using Malawian data, we show considerable heterogeneity in harvest value returns to cash cropping both within and between groups of farmers choosing different crop portfolios. Importantly, the results imply rational choices based on comparative advantage considerations of farming households: farmers self‐select into the activity where they expect higher gains and adopt cash crops when facing weaker market barriers.  相似文献   

8.
This study was carried out to assess cotton farmers’ willingness to pay (WTP) for pest management services in northern Benin. Targeted staggered control (TSC) has been introduced to reduce pesticide use in cotton cropping and generate an estimated benefit of FCFA48,800 (€74.40) per cotton hectare accruing from increased productivity and reduced pesticide cost. However, TSC application requires extra time for pest identification and scouting, and its adoption remains low due to the lack of funding to boost farmers’ awareness and cover training costs. An interval regression model was used to analyze responses to a double‐bounded contingent valuation survey with data collected from 300 cotton farmers. The results showed that 87.3% of cotton farmers were willing to pay for TSC services. Annual WTP per cotton hectare was estimated at FCFA16,962 (€25.80), revealing an existing demand for TSC adoption. Respondents' WTP was driven by farm and socio‐economic characteristics. Financial mechanisms managed by farmers could thus potentially foster technology adoption, and in turn, generate economic and environmental benefits.  相似文献   

9.
We estimate the perceived costs of legal requirements (‘coexistence measures’) for growing genetically modified (GM) Bt maize in Germany using a choice experiment. The costs of the evaluated ex‐ante and ex‐post coexistence measures range from zero to more than €300 per measure and most are greater than the extra revenue the farmers in our survey expect from growing Bt maize or than estimates in the literature. The cost estimates for temporal separation, the highest in our evaluation, imply that the exclusion of this measure in Germany is justified. The costliest measures of the ones that are currently applied in Germany are joint and strict liability for all damages. Our results further show that neighbours do not cause a problem and opportunities for reducing costs through agreements with them exist. Finally, we find that farmers’ attitudes towards GM crops affect the probability of adoption of Bt maize. Our results imply that strict liability will deter the cultivation of Bt maize in Germany unless liability issues can be addressed through other means, for example, through neighbours agreements.  相似文献   

10.
This study explores consumer acceptance and valuation of a genetically modified (GM) staple food crop in a developing country prior to its commercialization. We focus on the hypothetical introduction of a disease‐resistant GM banana variety in Uganda, where bananas are among the most important staple crops. A choice experiment is used to investigate consumer preferences for various attributes related to the banana (such as bunch size, technology, producer benefit, and price) and examine their opinions on GM foodstuff. Choice data come from 421 banana‐consuming households randomly selected from three regions of Uganda. A latent class model is used to investigate the heterogeneity in consumers’ preferences for selected attributes related to the banana and to profile consumers who are more or less likely to accept GM bananas. Our results reveal that there is significant heterogeneity in consumer preferences across our sample. GM bananas are valued the most by poorer households located in the rural areas of the Eastern region. These food‐insecure households would experience the highest benefits (i.e., welfare gains) from the commercial release of GM bananas. In contrast, urban consumers are less accepting of GM bananas, and they would experience significant welfare losses if GM banana is released. According to our welfare estimates, both the total welfare benefits acquired by the gainers and the total welfare losses borne by the losers of this technology are significant and large. These results suggest the need for further investigation of the overall welfare effects of the introduction of GM bananas on the Ugandan society as a whole.  相似文献   

11.
The unintended presence of traces of genetically modified (GM) crops in the harvests of non‐GM crops plays a prominent role in the debate over the coexistence of GM and non‐GM crops. One way to address the issue is the formation of GM‐free or GM‐only clubs. We model the decisions of individual farmers to cultivate either GM or non‐GM crops and combine this with a game theoretic model of club formation to investigate the feasibility of such clubs. We consider two liability regimes: GM farmers are liable or they are not. We consider two benchmarks: Nash equilibrium without negotiations and the efficient allocation and compare those with partial co‐operation through a Coasean club. We find that in both regimes a relatively large club can form but they are not always necessary to reach the efficient allocation. In fact, if farmers can freely decide under profit maximisation what to cultivate, they reach 95% of an efficient allocation. This holds independent of the property rights system and provides strong support for coexistence policies based on ex‐post liability such as in the US and Spain.  相似文献   

12.
High transaction costs and an absence of institutional infrastructure in developing countries prevent comprehensive enforcement of intellectual property rights and generate obstacles to the adoption of genetically modified (GM) crop technology. Governments of developing countries that are members of the World Trade Organization are faced with two options when licensing GM crop technology: (1) attempt to regulate GM crops to the standards of the Agreement on Trade‐Related Aspects of Intellectual Property (TRIPS) or (2) allow a black market in GM seeds and risk trade retaliation from the GM innovator's host country through a TRIPS trade complaint. This paper develops a conceptual model that frames the adopting country's range of licensing options, including a new levy system, and derives welfare measures for each option. The model illustrates how a levy on GM technology can be a welfare‐increasing policy for developing countries, and the operation of a levy is discussed. The conceptual model is applied to Brazil's soybean market and quantitative economic surplus measures are estimated within a calibrated welfare model for a range of licensing scenarios. The model's results suggest that a levy may interfere with the long‐term prospects for innovators to collect monopoly rents in adopting countries.  相似文献   

13.
The potential impact of climate change on Taiwan's agriculture   总被引:1,自引:0,他引:1  
This paper intends to estimate the potential impact of climate change on Taiwan's agricultural sector. Yield response regression models are used to investigate the climate change's impact on 60 crops. A price‐endogenous mathematical programming model is then used to simulate the welfare impacts of yield changes under various climate change scenarios. Results suggest that both warming and climate variations have a significant but non‐monotonic impact on crop yields. Society as a whole would not suffer from warming, but a precipitation increase may be devastating to farmers.  相似文献   

14.
The global demand for cashew nuts continues to increase steadily. However, many African countries face difficulties in marketing and adding value to the product. Using recent survey data of 391 cashew farmers in Ghana, this paper contributes to the growing evidence on the significance of contract farming (CF) in improving the welfare of rural households in developing countries. Specifically, the paper analyzes the factors that influence cashew farmers’ decisions to participate in CF, and the impact of participation on farmers’ performance. We employ a recently developed switching regression model with endogenous explanatory variables and endogenous switching to control for selection bias caused by observable and unobservable factors. The empirical results show that participation in CF significantly increases labor productivity and price margins, as well as cashew yields, and net revenues. A disaggregated analysis of the sample into farm size categories reveals that small‐sized cashew farms tend to benefit more through CF, compared to medium‐ and large‐sized farms.  相似文献   

15.
African countries continue to face deepening food crises that have been accentuated by the global food, energy, and financial crises. This situation is part of a long‐term structural problem: decades of under‐investments in agricultural sector and poor policies of support for smallholder farmers who form the bulk of the farming population. The inability of these farmers to achieve a supply response when commodity prices were high and market access was less of a problem suggests that there are multiple sets of binding constraints that continue to limit the potential of agricultural growth to reduce food security and poverty on the continent. This article reviews some of the historical trends that have hampered the performance of the agriculture sector. In addition, it reviews the impacts of more positive trends that could stimulate agricultural growth in Africa that could change the African agricultural landscape. The article however warns that there are more recent global developments and some continental challenges that could prevent or slow agricultural growth. These include the global financial crisis, public sector investments, inequities in global agricultural development policies, rush for agricultural lands by foreign investors, domestic commercial financing markets, climate change, and emerging carbon markets. The article argues that while opportunities for accelerated growth exists for African agriculture, new sets of policy instruments will be needed to support smallholder farmers to access new agricultural technologies, finance, reduce impacts of climate change, and adopt sustainable land use practices that can allow them to benefit from emerging global carbon markets.  相似文献   

16.
Policy makers, journalists and other commentators have hailed genetically modified (GM) crops as a ‘pro‐poor’ success in the developing world. Their confidence appears to be justified by the encouraging conclusions reached by academic studies on the performance and impacts of GM crops, which seem to provide convincing evidence of substantial benefits for smallholders in developing countries. However, a detailed, critical examination of studies on transgenic, insect‐resistant cotton in China, India and South Africa demonstrates that the technology's impacts have been evaluated and represented in selective and misleading ways. The performance and impacts of GM crops have in fact been highly variable, socio‐economically differentiated and contingent on a range of agronomic, socio‐economic and institutional factors. The shortcomings of the GM crop‐impacts literature have done a disservice to public and policy debates about GM crops in international development and impeded the development of sound, evidence‐based policy.  相似文献   

17.
Agronomic analyses of new technologies are often conducted under carefully controlled research station programs or trials managed by self‐selected farmers. Oftentimes, the technologies are then scaled up with minimal evaluation under real‐world conditions. Yet, the interim step between agronomic trials and large‐scale promotion is crucial to generate evidence on the social and economic impact of technologies that is both internally valid and generalizable. The article focuses on a participatory action research program in Malawi designed to test and identify scalable technology options to intensify the smallholder sector and contribute to poverty reduction and food and nutrition security. We examine the socioeconomic characteristics of farmers testing technologies and find evidence of systematic targeting of better‐endowed farmers. After controlling for observable differences using matching and a doubly robust estimator, we find evidence of early positive effects on maize yield and harvest value, although placebo tests suggest possible selection on unobservables. We note that attention should be given to program design and household characterization to better define and improve targeting criteria, technology selection, and external validity.  相似文献   

18.
Many mechanized crop producers and agribusinesses are fascinated with precision agriculture technology, but adoption has lagged behind the expectations. Among the reasons for slow adoption of precision agriculture technology is that initial users focused excessively on in‐field benefits from variable‐rate fertilizer application using regional average fertilizer recommendations. This article illustrates how greater use of site‐specific crop response information can improve variable rate input application recommendations. Precision agriculture is spatial information technology applied to agriculture. The technologies include global position systems (GPS), geographic information systems (GIS), yield monitoring sensors, and computer controlled within‐field variable rate application (VRA) equipment. Experimentation with these technologies is occurring everywhere there is large scale mechanized agriculture. Commercial use has been greatest in the US, where 43% of farm retailers offered VRA services in 2001. Except for certain high‐value crops like sugar beet, farmer adoption of VRA has been modest. The farm level profitability of VRA continues to be questionable for bulk commodity crops. The theoretical model and illustration presented here suggest that VRA fertilization has not yet reached its profitability potential. Most VKA field trials to date have relied upon existing state‐wide or regional input rate recommendations. Unobserved soil characteristics can potentially interact with an input to make its effect on yield vary site‐specifically within fields. Failure to use site‐specific response functions for VRA applications may lead to a misallocation of inputs just as great as that which results from using uniform applications instead of VRA. Agricultural economists have a long history of estimating output response to input applications. Several have started to develop tools to estimate site‐specific responses from yield monitor and other precision agriculture data. Likewise, agricultural economists have developed an important body of research results on information value based on managing variability—typically in temporal settings. With these tools, a major potential exists to develop further benefits from precision agriculture technologies that permit truly spatially tailored input applications.  相似文献   

19.
During the last three decades in sub‐Saharan Africa, development and research resources have concentrated on the higher‐rainfall and irrigated regions, especially on export crops and the principal food crops grown there. There has been much less concern and investment in semiarid regions without irrigation. Another negative factor has been the lack of public policy concern with the profitability of the basic food crops. With good weather, prices collapse. With bad weather, governments and NGOs dispense food crops as food aid or at subsidized prices. This article documents the importance of the demand side to facilitate diffusion of new technologies for the basic food commodities of semiarid regions—the traditional cereals. With farm programming models aggregated into a sector model, the combination of technological change and demand shifts for sorghum are evaluated in one semiarid region where the traditional cereals are concentrated. It focuses on combining policies to increase the prices farmers receive after introduction of technologies that use higher input levels. It also compares benefits of a strategy that focuses on yield and demand increases for a traditional cereal of the semiarid region, sorghum, with two alternative strategies for the higher‐rainfall zone.  相似文献   

20.
The objective of this study is to investigate the subjective determinants of farmers’ participation in output markets in five EU New Member States (NMS) characterised by large semi‐subsistence sectors. It employs quantile regression to model market participation reflecting the heterogeneity amongst farmers. The study also uses the Bayesian adaptive lasso to simultaneously select important covariates and estimate the corresponding quantile regression models. The empirical results show that only two variables affect all quantiles, while their effect varies across quantiles. Some of the remaining variables affect the share of output sold at the lower quantiles (i.e. for subsistence‐ and semi‐subsistence‐oriented farmers) only, whereas other variables are only significant at the upper quantiles (i.e. for more commercially oriented farms). Advisory services, and particularly agricultural business advice, and information and advice on markets and prices can facilitate the market participation of subsistence‐oriented farms.  相似文献   

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