Transgenic varieties and productivity of smallholder cotton farmers in China

Genetically modified cotton varieties have greater production efficiency for smallholders in farming communities in China. We also find that the adoption of Bacillus thuringiensis (Bt) cotton varieties leads to a significant decrease in the use of pesticides. Hence, we demonstrate that Bt cotton appears to be an agricultural technology that improves both production efficiency and the environment. In terms of policies, our findings suggest that the government should investigate whether or not they should make additional investments to spread Bt to other cotton regions and to other crops.     

The Dynamics of Pest Resistance Management: The Case of Refuge Fields for Bt Crops

We examine the optimal time‐variant refuge policy to manage pest resistance to Bacillus thuringiensis (Bt) crops in a finite, discrete‐time horizon model. We identify analytically the intertemporal effects of refuge fields on the pest population and its susceptibility. The shape of the optimal refuge policy and whether or not pest susceptibility should be exhausted completely at the end of the time horizon depend crucially on the values of a cost premium of Bt seeds and the fitness cost of resistance (over mortality of resistant pests) and are addressed via numerical simulations. We demonstrate the importance of modeling the dynamics of the biological system accurately, of defining a diploid (and not haploid) biological model, and of using a discrete‐time (rather than continuous‐time) framework.     

A Question of Integrity: Variants of Bt Cotton,Pesticides and Productivity in Pakistan

Bt cotton remains one of the most widely grown biotech crops among smallholder farmers in lower income countries, and numerous studies attest to its advantages. However, the effectiveness of Bt toxin, which depends on many technical constraints, is heterogeneous. In Pakistan, the diffusion of Bt cotton occurred despite a weak regulatory system and without seed quality control; whether or not many varieties sold as Bt are in fact Bt is also questionable. We utilise nationally representative sample data to test the effects of Bt cotton use on productivity. Unlike previous studies, we invoke several indicators of Bt identity: variety name, official approval status, farmer belief, laboratory tests of Bt presence in plant tissue, and biophysical assays measuring Bt effectiveness. Only farmer belief affects cotton productivity in the standard production model, which does not treat Bt appropriately as damage‐abating. In the damage control framework, all Bt indicators reduce damage from pests. Biophysical indicators have the largest effect and official approval has the weakest. Findings have implications for impact measurement. For policy‐makers, they suggest the need, on ethical and productivity grounds, to improve variety information and monitor variety integrity closer to point of sale.     

Bt Cotton,Pesticide Use and Environmental Efficiency in Pakistan

There is a broad literature on the impact of Bt cotton adoption in different countries, but few studies have explicitly looked at environmental and health effects from an economic perspective. We analyse the impact of Bt cotton on environmental efficiency in Pakistan, using farm survey data and a doubly heteroskedastic stochastic production function framework. Negative environmental and health effects of chemical pesticide use are quantified with the environmental impact quotient. Bt‐adopting farms have higher cotton yields, while using lower pesticide quantities and causing less environmental damage. Bt farms are both technically and environmentally more efficient than non‐Bt farms. Bt adoption increases environmental efficiency by 37%. Achieving the same reduction in negative environmental and health impact without Bt would cost conventional cotton farmers US$ 54 per acre in terms of foregone yields and revenues (7% of total revenues). Extrapolating this shadow price of the technology's health and environmental benefits to the total Bt cotton area in Pakistan results in an aggregate value of US$ 370 million. These benefits are in addition to the profit gains for Bt‐adopting farmers. Our results suggest that Bt technology can contribute to sustainable agricultural development.     

Why Do Some Bt-Cotton Farmers in China Continue to Use High Levels of Pesticides?

China was the first developing country to introduce Bt cotton on a large scale. This paper provides an indepth economic analysis of Bt cotton production by small-scale farmers in China. Data were collected in 2002 in Linqing County, in Shandong Province and comprised a season-long cotton production monitoring with 150 farmers and complementary household interviews. For quality assessment, the Bt toxin concentration of the various Bt varieties used by the farmers was determined for each plot. All farmers were growing insect resistant Bt cotton varieties. Yet, they sprayed high amounts of chemical insecticides, out of which 40% were extremely or highly hazardous. The paper reviews methodological issues inherent to impact assessment of crop biotechnology and identifies market and institutional failure as possible reasons for continued high pesticide use. Using the damage function methodology the coefficients for both damage control inputs, i.e., Bt varieties (measured as toxin concentration), and insecticide quantity were not significantly different from zero. Results show that absence of enabling institutions and lack of farmer knowledge can considerably limit the benefits of Bt cotton for small-scale farmers. The paper points out the importance to include the institutional conditions in the evaluation of agricultural biotechnology in developing countries.     

Ecosystem impacts of pesticide reductions through Bt cotton adoption

This article examines the ecosystem impacts of transgenic Bt cotton technology resulting from reduced chemical pesticide use. Employing unique panel data from smallholder farmers in India, negative environmental and health effects of pesticide use are quantified with the environmental impact quotient (EIQ), with and without Bt technology. An environmentally sensitive dynamic production function is estimated, treating the environmental risk of pesticide toxicity as an undesirable output in the production process. Negative externalities are significantly lower in Bt than in conventional cotton. The reduction in EIQ through Bt technology adoption has increased from 39 per cent during 2002–2004 to 68 per cent during 2006–2008. Bt adoption has also contributed to higher environmental efficiency. Environmental efficiency is influenced by the quality of Bt technology: high‐quality Bt seeds are associated with higher environmental efficiency than lower‐quality seeds.     

Bias from Farmer Self‐Selection in Genetically Modified Crop Productivity Estimates: Evidence from Indian Data

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.     

Farm-Level Economic Performance of Genetically Modified Cotton in Maharashtra, India

A study of the commercial growing of Bacillus thuringiensis (Bt) cotton in India, compares the performance of over 9,000 Bt and non-Bt cotton farm plots in Maharashtra over the 2002 and 2003 seasons. Results show that since their commercial release in 2002, Bt cotton varieties have had a significant positive impact on average yields and on the economic performance of cotton growers. Regional variation showed that, in a very few areas, not all farmers had benefited from increased performance of Bt varieties.     

Valuing financial,health, and environmental benefits of Bt cotton in Pakistan

Data from a farm survey and choice experiment are used to value the benefits of Bt cotton in Pakistan. Unlike previous research on the economic impacts of Bt, which mostly concentrated on financial benefits in terms of gross margins, we also quantify and monetize health and environmental benefits associated with technology adoption. Due to lower chemical pesticide use on Bt cotton plots, there are significant health advantages in terms of fewer incidents of acute pesticide poisoning, and environmental advantages in terms of higher farmland biodiversity and lower soil and groundwater contamination. Farmers themselves value these positive effects at US$ 79 per acre, of which half is attributable to health and the other half to environmental improvements. Adding average gross margin gains of US$ 204 results in aggregate benefits of US$ 283 per acre, or US$ 1.8 billion for the total Bt cotton area in Pakistan.     

Specification and Estimation of Production Functions Involving Damage Control Inputs: A Two-Stage, Semiparametric Approach

Productivity assessment of damage control inputs (such as pesticides) is complicated because their effect depends on the exposure to damage agents (such as pests). We discuss some open specification and estimation issues. The contribution is threefold. First, we elaborate the separability conditions for the damage control function and production function. Second, we employ a two-stage semiparametric technique to combine attractive features of both nonparametric and parametric approaches. Third, we model the interaction between pest exposure and damage control inputs by using slope dummies. An application to productivity analysis of small scale Bt cotton production in China illustrates the approach.     

The Sustainability of the Farm‐level Impact of Bt Cotton in China

The short‐run impact of Bt cotton adoption has been well documented; however, the sustainability of the impact remains unclear. In particular, pest resistance build‐up and secondary pest outbreaks have caused concern regarding the sustainability of this benefit. This paper analyses the effects and impact dynamics of Bt cotton adoption in China. Using six unique waves of panel data collected between 1999 and 2007, we show that the benefits of Bt cotton continue 10 years after it has been commercialised, albeit with evidence of a decline in the benefit since the early adoption period. Importantly, we also show that the benefit has been shared by both Bt and non‐Bt cotton adopters.     

Pesticide Productivity and Transgenic Cotton Technology: The South African Smallholder Case

This paper empirically investigates how the productivity of pesticide differs in Bt versus non‐Bt technology for South African cotton smallholders, and what the implications for pesticide use levels are in the two technologies. This is accomplished by applying a damage control framework to farm‐level data from Makhathini flats, KwaZulu‐Natal. Contrary to findings elsewhere, notably China, that farmers over‐use pesticides and that transgenic technology benefits farmers by enabling large reductions in pesticide use, the econometric evidence here indicates that non‐Bt smallholders in South Africa under‐use pesticide. Thus, the main potential contribution of the new technology is to enable them to realise lost productivity resulting from under‐use. By providing a natural substitute for pesticide, the Bt technology enables the smallholders to circumvent credit and labour constraints associated with pesticide application. Thus, the same technology that greatly reduces pesticide applications but only mildly affects yields, when used by large‐scale farmers in China and elsewhere, benefits South‐African smallholder farmers primarily via a yield‐enhancing effect.     

The Adoption of Genetically Modified Cotton and Poverty Reduction in Pakistan

This article employs a propensity score‐matching approach to examine the direct effects of adoption of Bacillus thuringiensis (Bt) cotton on yields, pesticide demand, household income and poverty, using cross‐sectional data from a survey of farmers in the Punjab province of Pakistan. Generally, the findings reveal that adoption of the new technology exerts a positive and significant impact on cotton yields, household income and poverty reduction, and a negative effect on the use of pesticides. The positive and significant impact of the technology on yields and household income is consistent with the potential role of new agricultural technology in directly reducing rural poverty through increased farm household income.     

The estimated ex ante economic impact of Bt cowpea in Niger,Benin and Northern Nigeria

Genetically modified (GM) crops could increase economic growth and enhance living standards in Africa, but political issues have slowed the use of biotechnology. This is the first study that assesses the potential impact of GM crops in Africa while considering the preferences of producers and consumers towards GMOs as well as the income and price risks they face. The study uses a choice experiment to estimate the ex ante economic impact of a novel technology, Bacillus thuringiensis (Bt) cowpea, on producers and consumers in Benin, Niger and northern Nigeria. The experiment involves the simulation of a market transaction similar to those in open air markets in West Africa. During the market simulation, respondents are informed about the advantages and disadvantages, including health risks, of Bt cowpea. The results from the study suggest that cowpea growers and consumers in Benin and northern Nigeria prefer Bt to conventional cowpea for health safety reasons. The results estimate that social welfare in Benin, Niger and northern Nigeria would increase by at least US$11.82 per capita annually with Bt cowpea, if seed sectors are operating smoothly. With inefficiencies in seed sectors and the potential for cowpea acreage increase, the estimated social welfare increase in the region would be about US$1.26 per capita annually.     

新疆棉农对农业面源污染防治的态度和支付意愿研究

农业面源污染问题已经成为我国面临的最严重的环境污染问题之一,农户对农业面源污染防治的态度和支付意愿研究,对于政府制定相关政策措施意义重大。分别采用李克特五点量表、条件价值评估法、多元有序Logistic模型回归等方法对(1)棉农对农业面源污染防治的态度,(2)棉农对农业面源污染防治的支付意愿(WTP),(3)影响棉农支付意愿的社会经济因素进行研究。结果表明:新疆棉农对农业面源污染防治的态度非常积极,但是当与自身利益相冲突时,则趋向于以牺牲环境为代价;新疆每户棉农对农业面源污染防治的支付意愿是113.96元/年,49.64%的被调查者选择的支付区间是[12,60)元/年,累计百分比占70.65%;农户的教育水平和是否参加过农业专业合作组织是新疆农户农业面源污染防治支付意愿的主要影响因素。基于此,得出结论并提出相应的对策建议。     

Genetically Modified Crops, Corporate Pricing Strategies, and Farmers' Adoption: The Case of Bt Cotton in Argentina

This article analyzes adoption and impacts of Bt cotton in Argentina against the background of monopoly pricing. Based on survey data, it is shown that the technology significantly reduces insecticide applications and increases yields; however, these advantages are curbed by the high price charged for genetically modified seeds. Using the contingent valuation method, it is shown that farmers' average willingness to pay is less than half the actual technology price. A lower price would not only increase benefits for growers, but could also multiply company profits, thus, resulting in a Pareto improvement. Implications of the sub-optimal pricing strategy are discussed.     

Adoption of Bt Cotton and Impact Variability: Insights from India

There is a growing body of literature about the impacts of Bacillus thuringiensis (Bt) cotton in developing countries. While many studies show remarkable benefits for farmers, there are also reports that question these results. Most previous studies consider impacts in deterministic terms, neglecting existing variability. Here we explain the main factors influencing the agronomic and economic outcomes. Apart from differences in pest pressure and patterns of pesticide use, germplasm effects can play an important role. Theoretical arguments are supported by empirical evidence from India. Better understanding of impact variability can help explain some of the paradoxes in the recent controversy over genetically modified crops.     

AGRICULTURAL PRICE POLICY,FOOD AID AND INPUT SUBSIDY REFORMS IN BURKINA FASO

This paper examines the agrarian decline in Burkina Faso that prompted structural adjustment reforms by the World Bank and the IMF in the early 1980s. Official interventions in the cereals, cotton and fertiliser sectors are examined, and an analysis made of regional impacts of the proposed reforms on producers and consumers. Counter-factual simulations with a multi-region, multi-commodity agricultural sector model are used to evaluate three policies: eliminating input subsidies, increasing official market commodity prices, and reducing food aid imports. Model results show that these reforms would improve agricultural-sector performance, but depend on cotton exports to pay for fertiliser, contrary to government self-sufficiency objectives. Relaxing capacity constraints on official marketing operations would also need to be eliminated to achieve reform objectives.