Joint production,land allocation,and the effects of the production flexibility program

An empirical land allocation model is developed and fit to production data of the top five crops in the USA and to crop output prices adjusted for direct payments and subsidies. The land allocation model based on the theory of the multiproduct firm allows for jointness in production, and it is extended to handle non-allocable inputs. Specifically, the model is used to analyze whether the Food Security Act of 1985, known as the 1985 Farm Bill, increased flexibility in land allocation decisions by comparing responsiveness of land allocation among the crops, before and after the passage of the 1885 Farm Bill, to changes in total land availability and changes in crop output prices. The results confirm that a structural change in land allocation dynamics took place after the passage of the 1985 Farm Bill. We show that more crops (wheat and soybeans, in particular) become more acreage responsive to the changes in total land available for production after 1985. For example, the results indicate that competition for acreage between corn and wheat is associated with the implementation of the 1985 Farm Bill. The results provide evidence that the onset of the increased acreage allocation flexibility by farmers originated in the policies of the 1985 Farm Bill. The study also demonstrates that a policy targeting a particular crop will inadvertently affect production of other crops. This study quantifies these indirect effects on the five major crops grown in the USA.     

Bundling agricultural technologies to adapt to climate change

Farmers can respond to climate change by modifying their technologies or management practices, or both. In this paper, we examine the choice of crop, irrigation, and cover as a bundled decision by a farmer. Using discrete choice analysis and a cross section of farms from Israel, we test whether these decisions are sensitive to climate and find that they are. In the case of Israel, the farmers completely substitute capital for climate. Simulating increase in temperature suggests that warming would lead Israeli farmers to shift mainly to orchards under cover and irrigation. But it is likely that bundling adaptations will provide flexibility and sustainability for future farmers in many locations under climate change conditions.     

Testing assumptions underlying economic research on transgenic food crops for Third World farmers: Evidence from Cuba, Guatemala and Mexico

Transgenic crop varieties (TGVs) are being promoted as essential for improving small-scale Third World (SSTW) agriculture. Most economic research on this topic makes critical, untested assumptions, including that farmers will choose TGVs over other varieties because TGVs are economically optimal and because farmers are risk neutral profit maximizers. We tested these assumptions using data from a survey of 334 farmers in 6 communities in Cuba, Guatemala and Mexico in which farmers ranked 4 real and hypothetical maize varieties for eating and sowing. Our results did not support these assumptions. Most farmers preferred farmer varieties for sowing and especially for eating, avoiding TGVs, a preference associated with being risk averse and with non-monetary preferences. Farmers more integrated into modern agriculture were more likely to choose TGVs. These results suggest that farmers most in need of support and most important for conserving genetic diversity are least favorable toward TGVs, and that alternative ways of improving SSTW agriculture should receive more attention.     

Testing assumptions underlying economic research on transgenic food crops for Third World farmers: Evidence from Cuba,Guatemala and Mexico

Transgenic crop varieties (TGVs) are being promoted as essential for improving small-scale Third World (SSTW) agriculture. Most economic research on this topic makes critical, untested assumptions, including that farmers will choose TGVs over other varieties because TGVs are economically optimal and because farmers are risk neutral profit maximizers. We tested these assumptions using data from a survey of 334 farmers in 6 communities in Cuba, Guatemala and Mexico in which farmers ranked 4 real and hypothetical maize varieties for eating and sowing. Our results did not support these assumptions. Most farmers preferred farmer varieties for sowing and especially for eating, avoiding TGVs, a preference associated with being risk averse and with non-monetary preferences. Farmers more integrated into modern agriculture were more likely to choose TGVs. These results suggest that farmers most in need of support and most important for conserving genetic diversity are least favorable toward TGVs, and that alternative ways of improving SSTW agriculture should receive more attention.     

Estimating bivariate yield distributions and crop insurance premiums using nonparametric methods

Modelling crop yield distribution is crucial in crop insurance premium setting. The correlation between different crop yields due to rotations or systemic risks requires estimation of joint yield distribution for multiple crops. In this article, we apply a nonparametric method to estimate bivariate yield distributions using farm-level yield data of wheat and corn in Shandong Province in China. Then, the simulated yields are used to evaluate the expected indemnity of one traditional and one hypothetical crop insurance programme. Our results reveal that the nonparametric bivariate method is very flexible in shaping the yield probability density functions to estimate local idiosyncrasies and correlation between two crops. It is also feasible to simulate the nonparametric yield distributions at a satisfying level of accuracy. The simulation results show that the hypothetical two-crop insurance contract can be more affordable to farmers than traditional individual crop insurance contracts.     

How efficient is maize production among smallholder farmers in Zimbabwe? A comparison of semiparametric and parametric frontier efficiency analyses

The controversial Fast Track Land Reform Programme in Zimbabwe that redistributes commercially-owned farmland to smallholder households has caused concerns about the efficiency of agricultural production in the country. In this paper, we estimate the efficiency of resource use among smallholder farmers in Zimbabwe when producing maize, the staple crop in the country. Using both a semiparametric model and a fully parametric stochastic frontier model, we find significant production shortfalls for smallholder maize production. While labor, capital, and land all significantly affect the total output, the estimated mean efficiency score for farms with less than 10 hectares of land (A1) appears to be under 0.75, and for the entire sample (A1 and A2) it ranges between 0.595 and 0.772. There clearly exists a great potential for maize farmers to improve the technical efficiency and increase the total output. Gender and age of the household head, access to extension services, and activities of other crops significantly affect the technical efficiency of smallholder maize production in Zimbabwe. We also find that all farms operate under increasing returns to scale and that the technical efficiency score tends to increase with the level of output.     

A Ricardian Analysis of the Distribution of Climate Change Impacts on Agriculture across Agro-Ecological Zones in Africa

This paper examines the distribution of climate change impacts across the sixteen Agro-Ecological Zones (AEZs) of Africa. We combine net revenue from livestock and crops and regress total net revenue on a set of climate, soil, and socio-economic variables with and without country fixed effects. Although African crop net revenue is very sensitive to climate change, combined livestock and crop net revenue is more climate resilient. With the hot and dry CCC climate scenario, average damage estimates reach 27% by 2100, but with the mild and wet PCM scenario, African farmers will benefit. The analysis of AEZs implies that the effects of climate change will be quite different across Africa. For example, currently productive areas such as dry/moist savannah are more vulnerable to climate change while currently less productive agricultural zones such as humid forest or sub-humid AEZs become more productive in the future. S. Niggol Seo is the Consultant to the World Bank.     

河北省农户采用蔬菜农艺节水集成技术意愿影响因素的实证分析——以藁城市为例

依据河北省藁城市种植设施蔬菜农户的调查资料,运用两项Logit模型,对农户采用蔬菜农艺节水集成技术意愿的影响因素进行实证研究。研究表明,蔬菜农艺节水集成技术应该重点向家庭年均总收入高、种植业收入占家庭总收入比重高、劳动力占家庭总人口比重高、户主男性、户主文化程度高的农户示范和推广;应加强引导示范户的示范、带动作用;通过各种途径强化节水宣传教育,使农户增强农业节水意识;政府应制订政策,合理提高农业水费,促进农户节水;进一步加大科研人员传播蔬菜节水技术信息的力度;政府应反思其工作方式,采用多数农民满意的扶持方式;尽量少用村干部、培训会方式宣传蔬菜节水技术信息。     

Agricultural impacts on water quality and implications for virtual water trading decisions

Research on the flow of virtual water associated with agricultural crop production and trade has focussed almost entirely on water quantity. It is pertinent to consider and quantify the opportunity costs in terms of reduced water quality associated with crop production. This paper investigates the impacts of water quality on virtual water trading by creating a proxy for water quality impacts by calculating the amount of water required to dilute nonpoint-source agrochemical inputs to relevant water quality guideline values. The quantity of water required for dilution of five agrochemicals (two nutrients; nitrogen and phosphorus and three insecticides; azinphos-methyl, chlorpyrifos and endosulfan) was estimated for five crops in South Africa (maize, wheat, sugar cane, citrus and cotton) and compared to consumption of irrigation water (blue water) and rainfall (green water) for the same crops. Results indicate that the volume of water required for dilution is similar to the total sum of green and blue water required for crop production, but significantly greater than blue water use (irrigation use). For all crops phosphorus losses require greater amounts of water for dilution than for nitrogen, while pesticides result in the greatest water quality use. Estimates of water quality use are based on assumptions for a number of input variables (i.e. fertilizer application rates, percentage loss of agrochemicals from cropped areas). A Monte Carlo analysis (5000 iterations) was run to randomly select input variables from within defined ranges. Water quality use was calculated and expressed as a factor of blue water use. For all crops the average factor indicated that the volume of water required for dilution of all agrochemicals was greater than that required for irrigation. The results of this study clearly indicate that the impacts of agriculture on water quality need to be considered in virtual water trading scenarios. The incorporation of a method to predict impacts on water quality provides a comparative tool which generates a more holistic frame of reference for decision making with regard to impacts on the water resource and virtual water trading.     

Crop Genetic Diversity, Productivity and Stability of Agroecosystems. A Theoretical and Empirical Investigation

This paper purports a model of farmers' crop choices in an uncertain environment. The model shows that profit maximizing farmers will choose a crop mix characterised by greater crop diversity if diversity is positively related to productivity and negatively correlated with production and income variability. An application using data from a Vavilov megadiversity spot, southern Italy, from 1970 up to 1993 is provided to test model hypotheses. It is found that interspecies crop genetic diversity is positively related to mean income and negatively related to the variance of income.     

Biofuel policies and the environment: Do climate benefits warrant increased production from biofuel feedstocks?

We examine whether climate benefits warrant policies promoting biofuel production from agricultural crops when other environmental impacts are accounted for. We develop a general economic-ecological modelling framework for integrated analysis of biofuel policies. An economic model of farmers' decision making is combined with a biophysical model predicting the effects of farming practices on crop yields and relevant environmental impacts. They include GHG emissions over the life cycle, nitrogen and phosphorus runoff, and the quality of wildlife habitats. We apply our model to crop production in Finland. We find that under current biofuel production technology the case for promotion of biofuels is not as evident as has been generally thought. Only reed canary grass for biodiesel is unambiguously desirable, whereas biodiesel from rape seed and ethanol production from wheat and barley cause in most cases negative net impacts on the environment. Suggested policies in the US and the EU tend to improve slightly the environmental performance of biofuel production.     

我国转基因农产品发展现状研究

基因技术早已成为一项众所周知且应用广泛的现代科技,中国还是世界八大作物起源中心之一,遗传资源十分丰富。2010年种植转基因作物的国家数目为29个,其中19个为发展中国家,中国为其中之一。种植面积上,中国位居第6位(约5 550万亩),排名前10位的其他国家分别是美国、巴西、阿根廷、印度、加拿大、巴拉圭、巴基斯坦、南非和乌拉圭。种植人数方面,中国约有650万农民种植转基因作物。种植作物主要为水稻、玉米、小麦、棉花、番茄等。我国在加强转基因产品生产的同时,对转基因产品的研发、法律监管和标识管理也在不断完善。     

Economic valuation of the vulnerability of world agriculture confronted with pollinator decline

There is mounting evidence of pollinator decline all over the world and consequences in many agricultural areas could be significant. We assessed these consequences by measuring 1) the contribution of insect pollination to the world agricultural output economic value, and 2) the vulnerability of world agriculture in the face of pollinator decline. We used a bioeconomic approach, which integrated the production dependence ratio on pollinators, for the 100 crops used directly for human food worldwide as listed by FAO. The total economic value of pollination worldwide amounted to €153 billion, which represented 9.5% of the value of the world agricultural production used for human food in 2005. In terms of welfare, the consumer surplus loss was estimated between €190 and €310 billion based upon average price elasticities of − 1.5 to − 0.8, respectively. Vegetables and fruits were the leading crop categories in value of insect pollination with about €50 billion each, followed by edible oil crops, stimulants, nuts and spices. The production value of a ton of the crop categories that do not depend on insect pollination averaged €151 while that of those that are pollinator-dependent averaged €761. The vulnerability ratio was calculated for each crop category at the regional and world scales as the ratio between the economic value of pollination and the current total crop value. This ratio varied considerably among crop categories and there was a positive correlation between the rate of vulnerability to pollinators decline of a crop category and its value per production unit. Looking at the capacity to nourish the world population after pollinator loss, the production of 3 crop categories - namely fruits, vegetables, and stimulants - will clearly be below the current consumption level at the world scale and even more so for certain regions like Europe. Yet, although our valuation clearly demonstrates the economic importance of insect pollinators, it cannot be considered as a scenario since it does not take into account the strategic responses of the markets.     

Valuing GM technologies using real options: the case of drought tolerant wheat in Australia

ABSTRACT

In this article we seek to estimate the value of a partially-developed crop technology from the perspective of the firm developing the technology. Firms need this value estimation to decide whether their technology will earn a sufficient return in the market to justify investing in it. However, determining the (ex-ante) value of the technology before it is commercialised is challenging as the technology is not yet in the market and hence the demand function has not yet been defined. An alternative valuation method is required. We use risk premiums, Monte Carlo simulation and real options analysis and we demonstrate this combination of valuation tools on wheat that is currently being developed in Australia to be drought tolerant. The results indicate that this drought tolerant wheat variety is likely to be adopted by farmers in most regions and has a pre-commercialisation value that justifies continued investment in its development. We also identified South Australia as a region in which the new variety would not be sufficiently valuable to farmers to see them adopt it and we consider possible explanations for this outcome.     

Insurance,credit, and technology adoption: Field experimental evidencefrom Malawi

Does production risk suppress the demand for credit? We implemented a randomized field experiment to ask whether provision of insurance against a major source of production risk induces farmers to take out loans to adopt a new crop technology. The study sample was composed of roughly 800 maize and groundnut farmers in Malawi, where by far the dominant source of production risk is the level of rainfall. We randomly selected half of the farmers to be offered credit to purchase high-yielding hybrid maize and groundnut seeds for planting in the November 2006 crop season. The other half of farmers were offered a similar credit package, but were also required to purchase (at actuarially fair rates) a weather insurance policy that partially or fully forgave the loan in the event of poor rainfall. Surprisingly, take-up was lower by 13 percentage points among farmers offered insurance with the loan. Take-up was 33.0% for farmers who were offered the uninsured loan. There is suggestive evidence that reduced take-up of the insured loan was due to farmers already having implicit insurance from the limited liability clause in the loan contract: insured loan take-up was positively correlated with farmer education, income, and wealth, which may proxy for the individual's default costs. By contrast, take-up of the uninsured loan was uncorrelated with these farmer characteristics.     

Increasing cooperation among plants,symbionts, and farmers is key to past and future progress in agriculture

The collective welfare of crop plants, their microbial symbionts, farmers, and society can be undermined by tragedies of the commons. A crop could increase resource allocation to grain if each plant invested less in sending roots into soil already explored by neighbors and less in stem growth. But evolutionary fitness depends on which plants capture the most soil resources and light (e.g., by growing taller than their neighbors), not just on the efficiency with which those resources are used. As for symbionts, with several strains infecting each plant, only host-imposed sanctions limit the fitness of strains that divert more resources to their own reproduction, at the expense of activities that benefit their host plant. Similarly, individual farmers do not necessarily benefit from pest- and resource-management practices that benefit farmers collectively or society as a whole. Plant breeders have increased crop yields by reversing past selection for individual fitness and they could breed for crops that would favor more-cooperative microbial symbionts. Better aligning interests among farmers and society may be more difficult.     

“哥伦布大交换”终结了“气候—治乱循环”吗?——对玉米在中国引种和农民起义发生率的一项历史考察

本文利用长期面板数据,对玉米被引入中国后,对明清农民起义发生率的影响进行了定量分析。分析结果显示,玉米播种时间和农民起义发生率存在U形关系:短期内,玉米的引种确实有助于降低气候灾害引发的农民起义的发生率,但这种效应是逐渐减弱的。到清朝中后期,玉米播种时间更久的地区甚至更易受水旱灾害危害,进而更易爆发农民起义。这说明了以玉米为代表的美洲作物的引种并未能让中国像欧洲国家那样摆脱"气候—治乱循环"。     

ECONOMIES OF SCALE AND SCOPE AND THE ECONOMIC EFFICIENCY OF CHINA'S AGRICULTURAL RESEARCH SYSTEM*

This article investigates economies of scale and scope and other potential sources of improvements in the economic efficiency of China's crop breeding, an industry at the heart of the nation's food economy. Using data covering 46 wheat‐ and maize‐breeding institutes from 1981 to 2000, we estimate cost functions for the production of new varieties at China's wheat‐ and maize‐breeding institutes. Our results indicate strong economies of scale, along with small to moderate economies of scope related to the joint production of new wheat and maize varieties. Cost efficiency increases significantly with increases in the breeders' educational status and with increases in access to genetic materials from outside the institute.     

不同规模农户农业生产效率差异及影响因素研究——基于DEA-Tobit模型的实证分析

文章基于小麦主产区4个省份946个不同规模农户的调查数据,利用DEA模型和Tobit回归模型分析了小农户和家庭农场农业生产效率的影响机制。结果表明:家庭农场的农业生产效率明显高于小农户的农业生产效率,家庭农场的生产效率与经营规模呈倒"U"型变化特征;在影响因素方面,土地肥沃程度与农业技术指导对小农户和家庭农场的农业生产效率均有显著正向影响;家庭农场更倾向于通过提高受教育程度和增加单块耕地面积来提升农业生产效率;而小农户的农业生产效率对农户年龄和农户从事农作物种植年限呈现出较强的依赖性。基于此,建议有针对性地加大农业技术指导,适度扩大农业生产经营规模,加强小农户与新型农业经营主体之间的合作与联合,促进农业生产向高质量发展。     

Town size and the consumer behaviour of Spanish households: a panel data approach

The aim of this paper is to analyse the effect of town size on the Spanish demand for food. The methodological approach followed in the study is to use panel data built from the Spanish Quarterly National Expenditure Survey to estimate a demand system. The use of this type of data allows control for unobserved time invariant heterogeneity as well as to take into account the time and the cross-section dimension of data. Four locations are distinguished: (1) less than 10000 inhabitants; (2) between 10000 and 100000 inhabitants; (3) between 100000 and 500000 inhabitants; and (4) more than 500000 inhabitants. Eight broad food categories are considered: (1) cereals and potatoes; (2) meat; (3) fish; (4) dairy products; (5) fats and oils; (6) fruits; (7) vegetables; and (8) other food. Income and price elasticities are calculated for each location. In general terms, two general conclusions can be drawn. First, results indicate that only slight changes in tastes have taken place during the analysed period; second, income and price elasticities use to decrease as town size increases.