Nutrient adequacy for poor households in Africa would improve with higher income but not necessarily with lower food prices.

Healthy diets are not affordable to all in Africa due to a combination of high food prices and low incomes. However, how African consumers might change demand patterns if prices or incomes were to change remains poorly understood. Using nationally representative household panel survey data from five sub-Saharan African countries, we model consumer preferences and examine how nutrient intake responds to changing food prices, total expenditures and other demand determinants. Here we find a stronger positive relationship between growth in poor consumers' total expenditures and their nutrient intake adequacy than has been previously documented. We also find that poor consumers' intake adequacy is especially sensitive to food staple prices in countries where one food staple dominates poor consumers' diets. In countries with multiple food staples, no single staple's price is a strong determinant of poor consumers' dietary intake adequacy.

The role of food preferences in determining diet quality for Tanzanian consumers.

Consumer preferences can be leveraged to magnify the impacts of agricultural investments and interventions on diets for all consumers in an economy, not just farmers. Using nationally representative panel data from Tanzania, we estimate demand for 19 food groups using an Exact Affine Stone Index censored demand system, which is flexible, utility-theoretic, controls for unobserved heterogeneity, and accounts for bias arising from endogenous prices. We find strong links between growth in household expenditures and improved diet quality. Also, staple grain prices are important determinants of nutrient intake. For poor consumers, e.g., protein and iron intake are more sensitive to maize price changes than to changing prices of other foods that contain more protein and iron. We use simulations to show that cash transfers and price vouchers targeting staple grains, pulses & nuts, and starchy staples could be effective in shrinking gaps between recommended and actual dietary intake for poor consumers.

Profitability of climate-smart soil fertility investment varies widely across sub-Saharan Africa.

Soil fertility investments in sub-Saharan Africa, where budgetary resources are scarce, must be well targeted. Using a causal forest algorithm and an experimental maize trial dataset matched with geocoded rainfall, temperature and soils data, we modelled site-specific, ex ante distributions of yield response and economic returns to fertilizer use. Yield response to fertilizer use was found to vary with growing season temperature and precipitation and soil conditions. Fertilizer use profitability-defined as clearing a 30% internal rate of return in at least 70% of the years-was robust to growing season climate and the fertilizer-to-maize price ratio in several locations but not in roughly a quarter of the analysed area. The resulting profitability-assessment tool can support decision makers when climate conditions at planting are unknown and sheds light on the profitability determinants of different regions, which is key for effective smallholder farm productivity-enhancing strategies.

Labor productivity and employment gaps in Sub-Saharan Africa.

Drawing on a new set of nationally representative, internationally comparable household surveys, this paper provides an overview of key features of structural transformation - labor allocation and labor productivity - in four African economies. New, micro-based measures of sector labor allocation and cross-sector productivity differentials describe the incentives households face when allocating their labor. These measures are similar to national accounts-based measures that are typically used to characterize structural change. However, because agricultural workers supply far fewer hours of labor per year than do workers in other sectors in all of the countries analyzed, productivity gaps shrink by half, on average, when expressed on a per-hour basis. Underlying the productivity gaps that are prominently reflected in national accounts data are large employment gaps, which call into question the productivity gains that laborers can achieve through structural transformation. Furthermore, agriculture's continued relevance to structural change in Sub-Saharan Africa is highlighted by the strong linkages observed between rural non-farm activities and primary agricultural production.

Linking knowledge with action in the pursuit of sustainable water-resources management.

Managing water for sustainable use and economic development is both a technical and a governance challenge in which knowledge production and sharing play a central role. This article evaluates and compares the role of participatory governance and scientific information in decision-making in four basins in Brazil, Mexico, Thailand, and the United States. Water management institutions in each of the basins have evolved during the last 10-20 years from a relatively centralized water-management structure at the state or national level to a decision structure that involves engaging water users within the basins and the development of participatory processes. This change is consistent with global trends in which states increasingly are expected to gain public acceptance for larger water projects and policy changes. In each case, expanded citizen engagement in identifying options and in decision-making processes has resulted in more complexity but also has expanded the culture of integrated learning. International funding for water infrastructure has been linked to requirements for participatory management processes, but, ironically, this study finds that participatory processes appear to work better in the context of decisions that are short-term and easily adjusted, such as water-allocation decisions, and do not work so well for longer-term, high-stakes decisions regarding infrastructure. A second important observation is that the costs of capacity building to allow meaningful stakeholder engagement in water-management decision processes are not widely recognized. Failure to appreciate the associated costs and complexities may contribute to the lack of successful engagement of citizens in decisions regarding infrastructure.

Evolution of the knowledge system for agricultural development in the Yaqui Valley, Sonora, Mexico.

Knowledge systems-networks of linked actors, organizations, and objects that perform a number of knowledge-related functions that link knowledge and know how with action-have played a key role in fostering agricultural development over the last 50 years. We examine the evolution of the knowledge system of the Yaqui Valley, Mexico, a region often described as the home of the green revolution for wheat, tracing changes in the functions of critical knowledge system participants, information flows, and research priorities. Most of the knowledge system's key players have been in place for many decades, although their roles have changed in response to exogenous and endogenous shocks and trends (e.g., drought, policy shifts, and price trends). The system has been agile and able to respond to challenges, in part because of the diversity of players (evolving roles of actors spanning research-decision maker boundaries) and also because of the strong and consistent role of innovative farmers. Although the agricultural research agenda in the Valley is primarily controlled from within the agricultural sector, outside voices have become an important influence in broadening development- and production-oriented perspectives to sustainability perspectives.

International trade in meat: the tip of the pork chop.

This paper provides an original account of global land, water, and nitrogen use in support of industrialized livestock production and trade, with emphasis on two of the fastest-growing sectors, pork and poultry. Our analysis focuses on trade in feed and animal products, using a new model that calculates the amount of "virtual" nitrogen, water, and land used in production but not embedded in the product. We show how key meat-importing countries, such as Japan, benefit from "virtual" trade in land, water, and nitrogen, and how key meat-exporting countries, such as Brazil, provide these resources without accounting for their true environmental cost. Results show that Japan's pig and chicken meat imports embody the virtual equivalent of 50% of Japan's total arable land, and half of Japan's virtual nitrogen total is lost in the US. Trade links with China are responsible for 15% of the virtual nitrogen left behind in Brazil due to feed and meat exports, and 20% of Brazil's area is used to grow soybean exports. The complexity of trade in meat, feed, water, and nitrogen is illustrated by the dual roles of the US and The Netherlands as both importers and exporters of meat. Mitigation of environmental damage from industrialized livestock production and trade depends on a combination of direct-pricing strategies, regulatory approaches, and use of best management practices. Our analysis indicates that increased water- and nitrogen-use efficiency and land conservation resulting from these measures could significantly reduce resource costs.