Changes in agricultural land use have important implications for environmental services. Previous studies of agricultural land-use futures have been published indicating large uncertainty due to different model assumptions and methodologies. In this article we present a first comprehensive comparison of global agro-economic models that have harmonized drivers of population, GDP, and biophysical yields. The comparison allows us to ask two research questions: (1) How much cropland will be used under different socioeconomic and climate change scenarios? (2) How can differences in model results be explained? The comparison includes four partial and six general equilibrium models that differ in how they model land supply and amount of potentially available land. We analyze results of two different socioeconomic scenarios and three climate scenarios (one with constant climate). Most models (7 out of 10) project an increase of cropland of 10–25% by 2050 compared to 2005 (under constant climate), but one model projects a decrease. Pasture land expands in some models, which increase the treat on natural vegetation further. Across all models most of the cropland expansion takes place in South America and sub-Saharan Africa. In general, the strongest differences in model results are related to differences in the costs of land expansion, the endogenous productivity responses, and the assumptions about potential cropland.
Understanding the capacity of agricultural systems to feed the world population under climate change requires projecting future food demand. This article reviews demand modeling approaches from 10 global economic models participating in the Agricultural Model Intercomparison and Improvement Project (AgMIP). We compare food demand projections in 2050 for various regions and agricultural products under harmonized scenarios of socioeconomic development, climate change, and bioenergy expansion. In the reference scenario (SSP2), food demand increases by 59–98% between 2005 and 2050, slightly higher than the most recent FAO projection of 54% from 2005/2007. The range of results is large, in particular for animal calories (between 61% and 144%), caused by differences in demand systems specifications, and in income and price elasticities. The results are more sensitive to socioeconomic assumptions than to climate change or bioenergy scenarios. When considering a world with higher population and lower economic growth (SSP3), consumption per capita drops on average by 9% for crops and 18% for livestock. The maximum effect of climate change on calorie availability is -6% at the global level, and the effect of biofuel production on calorie availability is even smaller.
Recent studies assessing plausible futures for agricultural markets and global food security have had contradictory outcomes. To advance our understanding of the sources of the differences, 10 global economic models that produce long-term scenarios were asked to compare a reference scenario with alternate socioeconomic, climate change, and bioenergy scenarios using a common set of key drivers. Several key conclusions emerge from this exercise: First, for a comparison of scenario results to be meaningful, a careful analysis of the interpretation of the relevant model variables is essential. For instance, the use of “real world commodity prices” differs widely across models, and comparing the prices without accounting for their different meanings can lead to misleading results. Second, results suggest that, once some key assumptions are harmonized, the variability in general trends across models declines but remains important. For example, given the common assumptions of the reference scenario, models show average annual rates of changes of real global producer prices for agricultural products on average ranging between -0.4% and +0.7% between the 2005 base year and 2050. This compares to an average decline of real agricultural prices of 4% p.a. between the 1960s and the 2000s. Several other common trends are shown, for example, relating to key global growth areas for agricultural production and consumption. Third, differences in basic model parameters such as income and price elasticities, sometimes hidden in the way market behavior is modeled, result in significant differences in the details. Fourth, the analysis shows that agro-economic modelers aiming to inform the agricultural and development policy debate require better data and analysis on both economic behavior and biophysical drivers. More interdisciplinary modeling efforts are required to cross-fertilize analyses at different scales.
Agriculture is unique among economic sectors in the nature of impacts from climate change. The production activity that transforms inputs into agricultural outputs involves direct use of weather inputs (temperature, solar radiation available to the plant, and precipitation). Previous studies of the impacts of climate change on agriculture have reported substantial differences in outcomes such as prices, production, and trade arising from differences in model inputs and model specification. This article presents climate change results and underlying determinants from a model comparison exercise with 10 of the leading global economic models that include significant representation of agriculture. By harmonizing key drivers that include climate change effects, differences in model outcomes were reduced. The particular choice of climate change drivers for this comparison activity results in large and negative productivity effects. All models respond with higher prices. Producer behavior differs by model with some emphasizing area response and others yield response. Demand response is least important. The differences reflect both differences in model specification and perspectives on the future. The results from this study highlight the need to more fully compare the deep model parameters, to generate a call for a combination of econometric and validation studies to narrow the degree of uncertainty and variability in these parameters and to move to Monte Carlo type simulations to better map the contours of economic uncertainty.
Assessments of climate change impacts on agricultural markets and land‐use patterns rely on quantification of climate change impacts on the spatial patterns of land productivity. We supply a set of climate impact scenarios on agricultural land productivity derived from two climate models and two biophysical crop growth models to account for some of the uncertainty inherent in climate and impact models. Aggregation in space and time leads to information losses that can determine climate change impacts on agricultural markets and land‐use patterns because often aggregation is across steep gradients from low to high impacts or from increases to decreases. The four climate change impact scenarios supplied here were designed to represent the most significant impacts (high emission scenario only, assumed ineffectiveness of carbon dioxide fertilization on agricultural yields, no adjustments in management) but are consistent with the assumption that changes in agricultural practices are covered in the economic models. Globally, production of individual crops decrease by 10–38% under these climate change scenarios, with large uncertainties in spatial patterns that are determined by both the uncertainty in climate projections and the choice of impact model. This uncertainty in climate impact on crop productivity needs to be considered by economic assessments of climate change.
Input subsidy programs have once again become a major plank of agricultural development strategies in Africa. Ten African governments spend roughly US$1 billion annually on input subsidy programs (ISPs), amounting to 28.6% of their public expenditures on agriculture. This article reviews the microlevel evidence on ISPs undertaken since the mid 2000s. We examine the characteristics of subsidy beneficiaries, crop response rates to fertilizer application and their influence on the performance of subsidy programs, the impacts of subsidy programs on national fertilizer use and the development of commercial input distribution systems, and finally the impact of ISPs on food price levels and poverty rates. The weight of the evidence indicates that the costs of the programs generally outweigh their benefits. Findings from other developing areas with a higher proportion of crop area under irrigation and with lower fertilizer prices—factors that should provide higher returns to fertilizer subsidies than in Africa—indicate that at least a partial reallocation of expenditures from fertilizer subsidies to R&D and infrastructure would provide higher returns to agricultural growth and poverty reduction. However, because ISPs enable governments to demonstrate tangible support to constituents, they are likely to remain on the African landscape for the foreseeable future. Hence, the study identifies ways in which benefits can be enhanced through changes in implementation modalities and complementary investments within a holistic agricultural intensification strategy. Among the most important of these are efforts to reduce the crowding out of commercial fertilizer distribution systems and programs to improve soil fertility to enable farmers to use fertilizer more efficiently. The challenges associated with achieving these gains are likely to be formidable.
Although the potential causes and consequences of recent rising international food prices have attracted widespread attention, many existing appraisals are superficial and/or piecemeal. This article attempts to provide a more comprehensive review of these issues based on the best and most recent research, as well as on fresh theoretical and empirical analysis. We first analyze the causes of the current crisis by considering how well standard explanations hold up against relevant economic theory and important stylized facts. Some explanations turn out to hold up much better than others, especially rising oil prices, the depreciation of the U.S. dollar, biofuels demand, and some commodity-specific explanations. We then provide an appraisal of the likely macro- and microeconomic impacts of the crisis on developing countries. We observe a large gap between macro and micro factors, which, when identifying the most vulnerable countries, often point in different directions. We conclude with a brief discussion of what ought to be learned from this crisis.
Agriculture can serve as an important engine for economic growth in developing countries, yet yields in these countries have lagged far behind those in developed countries for decades. One potential mechanism for increasing yields is the use of improved agricultural technologies, such as fertilizers, seeds, and cropping techniques. Public sector programs have attempted to overcome information-related barriers to technological adoption by providing agricultural extension services. While such programs have been widely criticized for their limited scale, sustainability, and impact, the rapid spread of mobile phone coverage in developing countries provides a unique opportunity to facilitate technological adoption via information and communication technology (ICT)-based extension programs. This article outlines the potential mechanisms through which ICT could facilitate agricultural adoption and the provision of extension services in developing countries. It then reviews existing programs using ICT for agriculture, categorized by the mechanism (voice, text, internet, and mobile money transfers) and the type of services provided. Finally, we identify potential constraints to such programs in terms of design and implementation, and conclude with some recommendations for implementing field-based research on the impact of these programs on farmers' knowledge, technological adoption, and welfare.
In many poor countries, the recent increases in prices of staple foods have raised the real incomes of those selling food, many of whom are relatively poor, while hurting net food consumers, many of whom are also relatively poor. The impacts on poverty will certainly be very diverse, but the average impact on poverty depends upon the balance between these two effects, and can only be determined by looking at real-world data. Results using household data for 10 observations on nine low-income countries show that the short-run impacts of higher staple food prices on poverty differ considerably by commodity and by country, but that poverty increases are much more frequent, and larger, than poverty reductions. The recent large increases in food prices appear likely to raise overall poverty in low-income countries substantially.
We study the relationship between pre‐school children's food consumption and household agricultural production. Using a large household survey from rural Ethiopia, we find that increasing household production diversity leads to considerable improvements in children's dietary diversity. However, we also document how this nonseparability of consumption and production does not hold for households that have access to food markets. These findings imply that nutrition‐sensitive agricultural interventions that push for market integration are likely to be more effective in reducing under‐nutrition than those promoting production diversity.
Collective‐action problems pervade all societies as well as ecological systems used by humans. Substantial evidence has accrued during the last several decades that human actors are able to solve some (but definitely not all) collective‐action problems on their own without external rules and enforcement imposed from the outside. In this article, I review some of the structural variables that have been found to affect the likelihood of collective action. Then, I address the need to base future work on collective action on a more general theory of human behavior than has been used to model collective action over the last five decades. In the last section, I discuss how structural variables affect the core relationships of reputation, trust, and reciprocity as these affect levels of cooperation.
This study assesses changes over the past decade in the farm size distributions of Ghana, Kenya, Tanzania, and Zambia, drawing on two or more waves of nationally representative population‐based and/or area‐based surveys. Analysis indicates that much of Sub‐Saharan Africa is experiencing major changes in farm land ownership patterns. Among all farms below 100 hectares in size, the share of land on small‐scale holdings under five hectares has declined except in Kenya. Medium‐scale farms (defined here as farm holdings between 5 and 100 hectares) account for a rising share of total farmland, especially in the 10–100 hectare range where the number of these farms is growing especially rapidly. Medium‐scale farms control roughly 20% of total farmland in Kenya, 32% in Ghana, 39% in Tanzania, and over 50% in Zambia. The numbers of such farms are also growing very rapidly, except in Kenya. We also conducted detailed life history surveys of medium‐scale farmers in each of these four countries and found that the rapid rise of medium‐scale holdings in most cases reflects increased interest in land by urban‐based professionals or influential rural people. About half of these farmers obtained their land later in life, financed by nonfarm income. The rise of medium‐scale farms is affecting the region in diverse ways that are difficult to generalize. Many such farms are a source of dynamism, technical change, and commercialization of African agriculture. However, medium‐scale land acquisitions may exacerbate land scarcity in rural areas and constrain the rate of growth in the number of small‐scale farm holdings. Medium‐scale farmers tend to dominate farm lobby groups and influence agricultural policies and public expenditures to agriculture in their favor. Nationally representative Demographic and Health Survey (DHS) data from six countries (Ghana, Kenya, Malawi, Rwanda, Tanzania, and Zambia) show that urban households own 5–35% of total agricultural land and that this share is rising in all countries where DHS surveys were repeated. This suggests a new and hitherto unrecognized channel by which medium‐scale farmers may be altering the strength and location of agricultural growth and employment multipliers between rural and urban areas. Given current trends, medium‐scale farms are likely to soon become the dominant scale of farming in many African countries.
Integrated Assessment studies have shown that meeting ambitious greenhouse gas mitigation targets will require substantial amounts of bioenergy as part of the future energy mix. In the course of the Agricultural Model Intercomparison and Improvement Project (AgMIP), five global agro-economic models were used to analyze a future scenario with global demand for ligno-cellulosic bioenergy rising to about 100 ExaJoule in 2050. From this exercise a tentative conclusion can be drawn that ambitious climate change mitigation need not drive up global food prices much, if the extra land required for bioenergy production is accessible or if the feedstock, for example, from forests, does not directly compete for agricultural land. Agricultural price effects across models by the year 2050 from high bioenergy demand in an ambitious mitigation scenario appear to be much smaller (+5% average across models) than from direct climate impacts on crop yields in a high-emission scenario (+25% average across models). However, potential future scarcities of water and nutrients, policy-induced restrictions on agricultural land expansion, as well as potential welfare losses have not been specifically looked at in this exercise.
The widespread growth of information and telecommunication technologies (ICTs) in rural areas of developing countries offers new opportunities to provide more timely and low‐cost information services to farmers, as well as assist in coordinating agricultural agents. Over the past decade, the number of public and private sector initiatives in this space has increased substantially, with over 140 deployments worldwide in 2015. While there is substantial potential for such services to address farmers’ and traders’ information and credit market constraints, economic research suggests that the impacts of such services on agricultural adoption, behavior and welfare is mixed. While this can, in part, be explained by the degree of the information asymmetry and the presence of other market failures in different contexts, research from other disciplines provides additional insights into these findings. In particular, work in the domain of human–computer interaction (HCI) focuses heavily on users’ interaction and experience with a given technology, thus explaining why users may not fully engage with ICT‐based agricultural interfaces. Furthermore, sociological and anthropological approaches study the provision of information and trust and how these may be altered by ICT platforms. Drawing upon these disciplines, we suggest that future ICT for agriculture initiatives should first seek to better understand the information and complementary market failures in a given context, in order to better understand whether information is a binding constraint. Second, even if information is missing, the information services provided should be of high quality and from a trusted source, which can be a challenge with some ICT platforms. Finally, such services should be delivered via platforms that build upon local ICT access and usage, paying particular attention to the gender digital divide.
Many developing countries grapple with high rates of farmland degradation and low agricultural productivity amidst increasing climate variability. Considerable efforts have been exerted to promote the diffusion of improved farmland management to address these challenges. Despite these efforts, adoption rates, especially of soil conservation and water harvesting technologies, are still low, which has been the subject of investigation in several studies in Ethiopia and elsewhere. Most studies on the adoption of these technologies, however, tend to focus on economic incentives only, paying little attention to the role of social capital. This article provides evidence of the effects of different dimensions of social capital on innovation adoption across households holding different levels of risk aversion. We address this issue by using cross section and panel data from Ethiopia. Results show that social capital plays a significant role in enhancing the adoption of improved farmland management practices. We also find evidence that the effect of social capital across households with heterogeneous risk taking behavior is different.
In the coming decades, an increasing competition for global land and water resources can be expected, due to rising demand for food and bio-energy production, biodiversity conservation, and changing production conditions due to climate change. The potential of technological change in agriculture to adapt to these trends is subject to considerable uncertainty. In order to simulate these combined effects in a spatially explicit way, we present a model of agricultural production and its impact on the environment (MAgPIE). MAgPIE is a mathematical programming model covering the most important agricultural crop and livestock production types in 10 economic regions worldwide at a spatial resolution of three by three degrees, i.e., approximately 300 by 300 km at the equator. It takes regional economic conditions as well as spatially explicit data on potential crop yields and land and water constraints into account and derives specific land-use patterns for each grid cell. Shadow prices for binding constraints can be used to valuate resources for which in many places no markets exist, especially irrigation water. In this article, we describe the model structure and validation. We apply the model to possible future scenarios up to 2055 and derive required rates of technological change (i.e., yield increase) in agricultural production in order to meet future food demand.
While international trade in organic products has grown significantly, understanding consumers’ preferences for imported organic foods has remained limited. This research examines the impact of country‐of‐origin labeling on US consumers’ choices of organic foods. Results show that consumer valuation of domestically produced organic broccoli was significantly higher than that of imported organic broccoli. Adding information about USDA organic certification standards/rules for imported products mildly increases consumer valuation of imported organic broccoli in some cases. These findings suggest that providing such information may have a positive impact on consumer willingness to purchase imported organic products.
Lack of clarity behind measurement and interpretation of statistics on gender and land leads to an inability to clearly articulate a policy response to the potential inequalities faced by women and men. This article sets out to explore, conceptually and empirically, the levels and relative inequalities in land rights between women and men in African countries. The first section of the article engages in a conceptual discussion of how to measure gendered‐land outcomes, what ownership and control mean in different contexts, and why attention to these factors is important for the development of gender and land statistics. The second section of the article systematically reviews existing evidence from microlevel large sample studies to summarize recent trends in land access, ownership, and control by sex. The third section presents new statistics from a variety of nationally representative and large‐scale unpublished data on gender and land in Africa. Results provide not only a nuanced understanding of the importance of measuring land indicators for gendered development in Africa and globally but also new statistics on a variety of land outcomes to aid stakeholders in the discussion of gender‐land inequalities.
This article examines how expected changes in climate are likely to affect agriculture in China. The effects of temperature and precipitation on net crop revenues are analyzed using cross-sectional data consisting of both rainfed and irrigated farms. Based on survey data from 8,405 households across 28 provinces, the results suggest that global warming is likely to be harmful to rainfed farms but beneficial to irrigated farms. The net impacts will be only mildly harmful at first, but the damages will grow over time. The impacts also vary by region. Farms in the Southeast will only be mildly affected but farms in the Northeast and Northwest will bear the largest damages. However, the study does not capture the indirect effects on farms of possible changes in water flow, which may be important in China.
We use a smooth transition vector error correction model to assess price relationships within the U.S. ethanol industry. Monthly ethanol, corn, oil, and gasoline prices from 1990 to 2008 are used in the analysis. Results indicate the existence of long‐run relationships among the prices analyzed. Strong links between energy and food prices are identified.