Technological change and risk management: an application to the economics of corn production

The paper investigates the linkages between technological change and production risk, with an application to corn. The effects of technology on risk exposure are analyzed. We define technological progress to be risk‐increasing (risk‐decreasing) if it increases (decreases) the relative risk premium. The analysis is applied to panel data from Wisconsin research stations. Conditional moments (including mean, variance and skewness) of corn yield, grain moisture and corn profit are estimated for different sites. We investigate how the trade‐off between expected return and the risk premium varies over time and over space. The empirical results indicate that technological progress contributes to reducing the exposure to risk as well as downside risk in corn production, although this effect varies across sites. They also stress the role of the relative maturity of corn hybrids as a means of managing risk.     

Mitigating rice production risks from drought through improving irrigation infrastructure and management in China

Rice, China's most important food crop, is highly dependent on irrigation, but an increasing number of extreme drought events have challenged rice production in many regions. This paper investigates the role of local irrigation infrastructure in improving farmers' ability to respond to drought and its effectiveness in mitigating the drought risk in rice production in China. The analysis relies on a moment‐based specification of the stochastic production function, capturing mean, variance and skewness effects. Using household survey data from 86 villages in five provinces, we jointly estimate farmers' adaptive irrigation decisions and their effects on rice yield and production risk. Our econometric analyses show that irrigation infrastructure in villages contributes to enhancing farmers' irrigation capacity in adapting to drought, and increased irrigation leads to a significant increase in mean yield and a reduction in exposure to risk as well as downside risk in rice production. The paper concludes with policy implications.     

On the Role of Risk Versus Economies of Scope in Farm Diversification With an Application to Ethiopian Farms

This article investigates the economics of farm diversification. The analysis assesses economies of diversification using a certainty equivalent measure. It identifies two components: one associated with expected income, and one associated with risk exposure. This integrates two lines of research explored in previous literature: economies of scope and risk management. We examine the roles played by complementarity, scale and concavity effects in economies of diversification. The approach is applied to diversification decisions made on Ethiopian farms, with a focus on production uncertainty. The econometric analysis finds large complementarity benefits, providing incentives to diversify. But this is tempered by (non)‐concavity effects that provide incentives to specialise. The analysis also documents how risk affects diversification, including both variance and skewness effects. It provides new insights on economic tradeoffs between farm diversification and specialisation.     

Self‐protection from weather risk using improved maize varieties or off‐farm income and the propensity for insurance

We investigate how self‐protection from the adoption of Improved Maize Varieties (IMV) and off‐farm income affects risk premiums for smallholder maize producers in Uganda. To unbundle these effects, we specify the cost of risk to explicitly capture four risk components—mean, variance, skewness, and kurtosis. Using unique plot‐level panel data for Uganda, we estimate and test moments of a flexible production function based on an expanded form of the Johnson S_U family distribution and proceed to simulate the degree of responsiveness of risk premiums and welfare estimates to marginal changes in the share of land under IMV and off‐farm income. Scenarios of joint adoption of IMV accompanied with low and high application of inorganic fertilizer, and the effect of off‐farm income when there is high and low supply of farm labor are examined. Results show that the use of IMV and off‐farm income substantially reduces risk premiums and the individual effect is much higher under low fertilizer application and high supply of farm labor, respectively. Thus implying that self‐protection is likely to reduce the propensity for index insurance especially if its design fails to consider the reduction in downside risk.     

Farmer management of production risk on degraded lands: the role of wheat variety diversity in the Tigray region, Ethiopia

This article investigates the effects of wheat genetic diversity and land degradation on risk and agricultural productivity in less favored production environments of a developing agricultural economy. Drawing production data from a household survey conducted in the highlands of Ethiopia, we estimate a stochastic production function to evaluate the effects of variety richness, land degradation, and their interaction on the mean and the variance of wheat yield. Ethiopia is a center of diversity for durum wheat and farmers manage complex variety mixtures on multiple plots. Econometric evidence shows that variety richness increases farm productivity. Variety richness also reduces yield variability but only for high levels of genetic diversity. Simulations with estimated parameters illustrate how planting more diverse durum wheat varieties on multiple plots contribute to improving farmer's welfare.     

Volatility Forecasting and Time‐varying Variance Risk Premiums in Grains Commodity Markets

In this paper we examine empirically the predictive power of model‐free option‐implied variance and skewness in wheat, maize and soybeans derivative markets. We find that option‐implied risk‐neutral variance outperforms historical variance as a predictor of future realised variance for these three commodities. In addition, we find that risk‐neutral option‐implied skewness significantly improves variance forecasting when added in the information variable set. Variance risk premia add significant predictive power when included as an additional factor for predicting future commodity returns.     

RISK,UTILITY AND STOCKING RATE*

A simple utility-based model of risky wool production is presented. Evaluation of the model indicates the effect on optimal stocking rate of changes in the degree of risk aversion, farm area, variable cost, fixed cost, wool cut, wool price, variance of wool price, climatic variability and tax rate. It is shown that the utility hypothesis implies a lower optimal stocking rate than does expected profit maximization and hence implies a discrepancy between private and public optimal resource use which it is suggested, might be mitigated by a progressive bounty on wool production.     

Crop genetic diversity, farm productivity and the management of environmental risk in rainfed agriculture

This paper presents an assessment of the linkages between cropgenetic diversity, farm productivity and risk management. Aflexible moment-based approach is used to analyse the impactof crop genetic diversity on the mean, variance and skewnessof yield. Using farm-level data from Sicily (Italy), econometricevidence shows how crop genetic diversity can increase farmproductivity and reduce risk exposure. The empirical resultsindicate that crop genetic diversity can reduce variance, butonly if pesticide use is low. Furthermore, high diversity levelscan reduce downside risk exposure (e.g. the risk of crop failure).This provides useful insights on the linkages between resilienceand crop genetic diversity.     

The firm size,farm size,and transaction costs: the case of hazelnut farms in Turkey

This study analyzes the effects of transaction costs on the size of hazelnut farms in Turkey. The study finds that higher land slope and higher variance of rain, as transaction‐cost‐increasing natural effects, lead to smaller hazelnut land holdings. High slope and weather variation can increase the costs of monitoring the laborers, make moving inputs or output up and down harder, limit the use of machinery, and reduce contractual performance of labor contracts. For farm production functions, land is a complex input with measurable interactions with nature. Contrary to common production theory approaches that take natural properties of land as given, the study develops a production function that incorporates natural properties, such as, slope and rain variance. The study utilizes two separate data sets for the estimations. The first data set explores the characteristics of hazelnut farmers, while the second one analyzes the regional characteristics of hazelnut farms.     

Production Risks and Food Security under Alternative Technology Choices in Malawi: Application of a Multinomial Endogenous Switching Regression

Employing nationally representative data, we investigate the impact of Sustainable Intensification Practices (SIPs) on farm households’ food security, downside risk and the cost of risk in Malawi. The analysis relies on a flexible moment‐based specification of a stochastic production function in a multinomial endogenous switching regression framework to correct for the selection bias stemming both from observed and unobserved heterogeneity. A quantile moment approach is used to estimate the cost of risk. After controlling for the effects of unobserved heterogeneity and several observable variables on maize production and downside risk functions, estimation results show that the adoption of SIPs increases food security and reduces downside risk exposure and the cost of risk. We estimate greater food security and larger reduction in downside risk from simultaneous adoption of both crop diversification (maize–legume intercropping and rotations) and minimum tillage, suggesting that there are complementary benefits from these practices. We find most of the cost of risk comes from exposure to downside risk. Our findings imply that in dealing with production risks development agents should encourage the adoption of agronomic and resource‐management practices along with other risk mitigation and food security improving strategies.     

Modeling skewness with the linear stochastic plateau model to determine optimal nitrogen rates

Accurate modeling of skewness is needed to increase the actuarial fairness of crop insurance. We test Day's conjecture that crop yield skewness becomes negative as nitrogen rates increase and determine how well a linear response stochastic plateau (LRSP) production function matches the pattern of observed skewness using four long‐term nitrogen experiments. Stillwater wheat is consistent with Day's conjecture, but the skewness for Lahoma and Altus wheat yields as well as Altus cotton yields are not. The LRSP assumes normal random effects and can explain only a small part of observed skewness, so a new LRSP with skew‐normal random effects is introduced, which comes closer to explaining the observed skewness and should increase the accuracy of nitrogen rate recommendations. Negative skewness reduced optimal nitrogen rates and positive skewness increased optimal nitrogen rates.     

ESTIMATING RISK EFFECTS IN CHINESE FOODGRAIN PRODUCTION

Given the importance of Chinese foodgrain production both in China and in the world food market, it is useful to explore the sources of the increased variabilities of China's foodgrain production (Stone and Zhong, 1989). A production function with composite error structure and a heteroscedastic disturbance is applied to cross-section and time-series data from China. The function provides information on the contributions of inputs to production variance and therefore on risk. It is found that production variance is positively related to sown area, chemical fertiliser and irrigation, and is negatively related to electricity use. However, most of the estimates determining the marginal risk effects lack statistical significance. This suggests that the measured controllable factors do not contribute very significantly to Chinese foodgrain production variability.     

Integration of VaR and expected utility under departures from normality

This article identifies the level of the expected utility (EU) risk aversion and Value-at-Risk (VaR) confidence level that yield the same choice from a given distribution of outcomes, and thus allow for consistent application of the two criteria. The result for a given distribution is an explicit mapping between risk aversion under EU and VaR, for both normal and nonnormal distributions. The Cornish–Fisher expansion is used to establish adjusted mean-deviates for nonnormal outcome distributions and the investor's preference function is expanded to include elements for variance, skewness, and excess kurtosis. A farm-level application with nonnormal revenue distribution illustrates these approaches.     

Does mixed crop‐livestock farming lead to less diversified diets among smallholders? Evidence from Laos

Malnourishment continues to remain a challenge in developing countries. As the undernourished are largely smallholder farmers, it is widely assumed that farm diversification and mixed crop‐livestock agricultural systems can help alleviate this problem. However, empirical evidence in this context is limited. Hence, we use a two‐year panel's data from Laos to examine whether farm production diversity as well as a mixed crop‐livestock farming system improves household dietary diversity among smallholder farmer. The results from the fixed effects regression indicate that although farm production diversity does lead to a higher dietary diversity, the effect diminishes with continued farm diversification. The counterfactual analysis from the endogenous switching regression reveals that mixed crop‐livestock farming systems do not necessarily enhance dietary diversity. However, we further find that purchasing food from the markets plays an important role in enhancing the dietary diversity of rural smallholder farmers.     

挣值法在土地开发整理工程成本偏差分析中的运用研究

研究目的:本文借鉴项目管理中的重要技术方法——挣值法的基本原理,试图基于工作分解结构构建土地开发整理工程成本偏差分析框架,为解剖土地开发整理工程竣工成本偏差的成因、全面反映土地开发整理工程规划设计和费用执行偏差情况提供一个参考工具或报告框架。研究方法:文献资料法,比较借鉴法。研究结果:通过增加实际完成的工程的预算价格的计算,与实际工程结算价格、计划工程预算、实际工程成本等进行比较,得到单价变化引起的成本偏差、工程量变化引起的成本偏差、结算价格浮动系数、工程量执行系数、费用执行系数等分析指标,基于工作分解结构(WBS)构建了土地开发整理工程成本偏差分析框架。研究结论:挣值法可运用于土地开发整理工程成本偏差分析。     

Adverse Shocks in Agriculture: The Assessment and Management of Downside Risk

This paper investigates the assessment and effects of adverse shocks on agricultural production, with an application to corn yield. Adverse shocks are assessed by the probability of facing low yields, i.e. by the probability of being exposed to downside risk. Defined in terms of willingness‐to‐pay to eliminate risk, the ex‐ante cost of facing adverse events is evaluated under prospect theory. Prospect theory is relevant in the evaluation of adverse shocks as it identifies a role for both loss aversion and oversensitivity to low probability events. The analysis is applied to experimental data on corn yield in the US Corn Belt. Estimates show how the distribution of corn yield is affected by management and technology. Implications for the cost of adverse shocks are examined. The results show how management and technology can reduce exposure to adverse shocks and lower the cost of risk in agriculture.     

Crop Yield Skewness Under Law of the Minimum Technology

No satisfactory motivation has been forwarded in favor of any crop yield distribution, including the normal. This article explores the foundations of yield distributions for the Law of the Minimum resource constraint technology at the plot level of analysis. With independent, identical, uniform resource availability distributions the yield skew is positive, whereas it is negative whenever the distributions are normal. Simulations show how asymmetries in resource availabilities determine skewness. It is suggested that a negative yield skew occurs whenever production is tightly controlled so that the left tails of some resources availabilities distributions are thin. Irrigation may increase yield skewness.     

我国玉米主产区生产成本效率分析*——基于吉林、河北和四川3省调研数据

［目的］通过实证分析2017年吉林、河北和四川3个玉米主产省份的玉米生产成本效率，及其与生产要素的相关性，为提高玉米生产成本效率，降低生产成本，研究提出有效的政策建议。［方法］文章采用2017年吉林、河北和四川3省的玉米生产投入情况的调研数据，运用数据包络分析法测算3省的玉米生产成本效率，通过最小二乘法测度要素投入与成本效率的相关性。［结果］吉林省（070）的成本效率远高于河北（039）和四川（035），3省的种子、化肥和机械投入对成本效率的影响存在较大地区差异。河北省和四川省的劳动力对成本效率的影响较大，吉林省的土地机会成本对成本效率的影响较大。［结论］建议调整种植结构，改善种植方式，整合资源，以增强农业生产能力。     

Production risk,risk aversion and the determination of risk attitudes among Spanish rice producers

Agricultural production is subject to risk and the attitudes of producers toward risk will influence input choices insofar as these affect production risk. Risk attitudes in turn may be affected by certain socioeconomic characteristics of producers. Using 2004 survey data from a cross‐section of 130 Spanish rice farms, we estimate risk‐aversion coefficients of farmers and investigate the influence of a series of socioeconomic variables on their risk attitudes. Our results show that farmers exhibit risk‐averse behavior and that risk attitudes are related to a series of socioeconomic characteristics. In particular, the belief that the farm will continue after the producer retires is found to increase the degree of risk aversion, while age is found to have nonlinear effects on risk aversion. Off‐farm income, especially from nonagricultural activities, is found to reduce risk aversion. Neither the educational level of the producer nor the presence of dependents on the household is found to have an effect on risk preferences. Regarding the production technology, we find that land, labor, and fitosanitary products are risk‐reducing inputs, whereas capital, seeds, and fertilizer all increase risk.     

村集体协调在抑制土地托管风险中何以失效 ——基于委托代理理论的视角

研究目的:基于委托代理视角,探究村集体协调在抑制土地托管风险中失效的原因。研究方法:构建村集体协调下土地托管风险的四方演化博弈模型,基于675份实地调查数据,仿真分析并实证检验村集体协调对土地托管风险的影响。研究结果:(1)村集体协调能够降低土地托管风险,但这一作用的发挥受委托代理关系的调节,委托代理问题的存在使村集体协调在抑制土地托管风险中失效。(2)村干部的协调态度与协调成本对村集体协调效应的发挥具有调节作用,村干部的协调态度发挥正向调节作用,协调成本发挥负向调节作用。(3)协调态度的调节效应在兼业户中最显著,其次为专业大户,在小规模纯农户中未发挥作用。协调成本的调节效应在小规模纯农户中最为明显,专业大户与兼业户次之。研究结论:强化村集体的协调作用;鼓励村干部转变协调态度,降低协调成本;因人施策防范化解土地托管风险。