The nutrition transition and agricultural transformation: a Preston curve approach

The nutrition transition in diets and health is closely tied to other aspects of economic development, including agricultural transformation and urbanization as well as demographic change and epidemiological transition from infectious to noncommunicable disease. Over time, dietary patterns typically shift from widespread inadequacy of many foods and nutrients, especially for children and mothers, into surplus energy intake and rising obesity with continued inadequacy of healthier foods. Diet‐related diseases remain the largest single cause of premature death and disability in all regions. This article combines food availability and dietary intake data from more than 100 countries over 30 years with a wide range of other evidence to characterize the nutrition transition and its association with changes in agricultural production and the food environment, asking how future dietary patterns might be steered toward healthier outcomes as national incomes grow.     

China’s Agricultural Policy Transition: Impacts of Recent Reforms and Future Scenarios

This article reviews recent developments in China’s agricultural domestic support policy, especially the transition from taxing farmers and agriculture to providing direct subsidies to grain production and purchased inputs. A model‐based quantitative analysis on the effects of these policy changes is presented. Simulation results suggest that recent policy changes have achieved the declared policy goals of increasing grain production and boosting farm income. Much of the increase in grain production and farm income can be attributed to higher per unit return to arable land, land reallocation to grain production and extra agricultural employment triggered by the policy changes. Based on the assumption that China’s public assistance to agriculture and farmers will continue and rise, two hypothetical future scenarios are simulated. Using all the support permitted under WTO de minimis limits with existing instruments, China’s policy will increase grain production, change trade patterns seemingly contrary to China’s comparative advantage, increase rural employment and significantly increase farm income (by more than 12%). If, however, decoupled instruments are applied to raise China’s agricultural domestic support to the same level, China’s agricultural production and trade will remain unchanged, rural employment remain stable, but farm income will be increased by nearly 15%.     

The growing importance of the former USSR countries in world agricultural markets

The major countries of the former Soviet Union—specifically Russia, Ukraine, and Kazakhstan—are becoming increasingly important in world agricultural markets. The two main developments are that this region has become a large grain exporter, especially of wheat and barley, and Russia a big agricultural importer, especially of meat. These trends should continue for the next decade. However, policies to expand the livestock sector could mitigate these developments, as increased domestic meat production would reduce both meat imports and surplus feed grain for export. Also, further growth in the region's grain exports will require improvement in the infrastructure for storing and transporting grain.     

Smallholder land ownership in Kenya: distribution between households and through time

This study uses panel data to demonstrate two dimensions of land ownership: the distribution between households at a given time and changes within a household over time. We note that recognizing the latter dimension is only possible when analyzing rare long‐term panel data. We estimate a model for land ownership using a version of the correlated random effects estimator to uniquely identify the determinants of both dimensions amongst Kenyan smallholders. We find life cycle effects are a key determinant of both distributions, and identify important ways in which initial conditions such as inheritance and off‐farm income relate to the dynamics of ownership. We find that population density is a key determinant of differences between households, but also that a given household's land ownership is not affected in the short term as population density increases around them. Controlling for population density, households own more land when they are closer to road networks where the economic value of land is higher. We find important vulnerabilities for the land security of widows, but this vulnerability is geographically heterogeneous.     

Analyzing the welfare‐improving potential of land in the former homelands of South Africa

This article contributes to the debate on the role of land in reducing poverty in rural South Africa. It uses the year of arrival in the former homelands as an instrument for land access and size. This identification strategy is based on the fact that African households were forcibly relocated to the homelands during the apartheid. Due to increasing population pressure, later arrivals were less likely to be assigned land. The results show that land has a large positive effect on household welfare. Because the homelands are relatively disadvantaged areas, these results provide a lower bound for the positive effects of land on household welfare.     

Prices,institutions, and determinants of supply in the Malian cotton sector

Cotton, both a source of livelihood for millions of poor rural households and a major source of export revenues, is a vital commodity for the economic and social development of Mali. Inefficiencies in the Malian cotton system at the ginnery and producers’ cooperative levels (e.g., late payment to farmers and poorly functioning credit schemes) have recently led to an important decline in supply, threatening the sustainability of the sector. Using regional data from 1998/1999 to 2008/2009, this study aims to quantitatively assess the contribution of key determinants, such as cotton prices and timely payment, toward the downward trend in cotton area. A dynamic supply model, based on adaptive expectations and partial adjustment, is employed to estimate the effects of prices and institutional factors, such as credit recovery rates and date of payment to farmers, on the Malian cotton supply. Results show that supply responds significantly to cotton prices relative to cereal and fertilizer prices. Date of payment varies across agricultural cycles and late payment negatively influences land devoted to cotton. Low credit repayment rates create disincentives to grow cotton. Therefore, the revitalization of the Malian cotton sector depends upon getting both prices and institutions right.     

Adoption of weather‐index insurance: learning from willingness to pay among a panel of households in rural Ethiopia

In this article we examine which farmers would be early entrants into weather‐index insurance markets in Ethiopia, were such markets to develop on a large scale. We do this by examining the determinants of willingness to pay for weather insurance among 1,400 Ethiopian households that have been tracked for 15 years as part of the Ethiopian Rural household Survey. This provides both historical and current information with which to assess the determinants of demand. We find that educated, wealthier individuals are more likely to purchase insurance. Risk aversion is associated with low insurance take‐up suggesting that models of technology adoption can inform the purchase and spread of weather index insurance. We also assess how willingness to pay varied as two key characteristics of the contract were varied and found that basis risk reduces demand for insurance particularly when the price of the contract is high, and that provision of insurance through groups is preferred by female headed households and individuals with lower levels of education.     

How do Agricultural Programmes Alter Crop Production? Evidence from Ecuador

Evaluating agricultural programmes requires considering not only the programmes’ influence on input and output indicators, but also considering the relationship between these indicators as embodied in the production technology. This article examines the impact on production of an intervention in the Ecuadorian Sierra designed to improve returns to potato production through training and through linking smallholders to high‐value markets. Critical to identifying the impact of the programme is the careful construction of a counterfactual and meticulous data collection. To assess the impact of the programme on production, a weighted estimation, where weights are constructed through propensity score matching, is employed to estimate a production function within a damage abatement framework. The function incorporates a series of interaction terms to assess the impact of the programme on the production technology. The findings provide evidence that the programme enhances yields both through a general shift in technology as well as increased input use. The results suggest that the use of effective farming techniques that are learned through the programme induce this technological shift.     

Shifting cultivation and forest pressure in Cameroon

Shifting cultivation is often blamed as a principal cause of deforestation in tropical Africa. It is claimed that the practice is unsustainable because shortened fallow lengths result in soils too degraded to support forest vegetation. The decline in fallow lengths is often attributed to increases in population density and greater market participation. The conventional wisdom makes several claims that are as yet unsubstantiated. This article investigates whether there is evidence to support two of these claims in southern Cameroon. First, using both cross‐sectional and panel data, I find that there is indeed a robust negative association between fallow lengths and population density in the study area and weaker evidence for a negative relationship between fallow lengths and market participation. Second, a stochastic frontier production function approach is used to investigate the marginal contribution of fallow to output. Results indicate that fallow lengths are not low enough to be affecting yields and therefore do not appear to be resulting in declines in soil fertility. Thus overall, while some of the assumptions of the conventional wisdom appear to be true, there is little evidence to support its dramatic conclusion that shifting cultivators are causing deforestation in the forested region of Cameroon.     

Restricted maximum likelihood estimation under Eisenhart model Ill

For a balanced two-way mixed model, the maximum likelihood (ML) and restricted ML (REML) estimators of the variance components were obtained and compared under the non-negativity requirements of the variance components by L ee and K apadia (1984). In this note, for a mixed (random blocks) incomplete block model, explicit forms for the REML estimators of variance components are obtained. They are always non-negative and have smaller mean squared error (MSE) than the analysis of variance (AOV) estimators. The asymptotic sampling variances of the maximum likelihood (ML) estimators and the REML estimators are compared and the balanced incomplete block design (BIBD) is considered as a special case. The ML estimators are shown to have smaller asymptotic variances than the REML estimators, but a numerical result in the randomized complete block design (RCBD) demonstrated that the performances of the REML and ML estimators are not much different in the MSE sense.