This paper assesses the Subramanian and Deaton (S–D) approach for imputing the caloric intake of households from food prepared away from home (FAFH) and composite foods (CF) by juxtaposing it with the imputations of alternative approaches, and extends these approaches to four additional nutrients—vitamin A, iron, zinc, and calcium. The apparent relative nutritional insignificance of FAFH and CF in Bangladesh obfuscates our efforts to assess alternatives to the S–D approach to imputation, and we remain uncertain about the relative value of the alternative imputation approaches examined. FAFH and CF—although widely consumed in Bangladesh—constitute a relatively unimportant source of nutrients, regardless of how the nutrient content of FAFH and CF is imputed.

Urbanization has had a major impact on livelihoods in Ghana and throughout Africa as a whole. However, much research on urbanization has focused on effects occurring within cities, while there is insufficient understanding of its effects on rural areas. This paper examines the impact of urbanization—through a typology of districts—on rural livelihoods in Ghana. The country’s districts are classified into seven spatial groups according to the size of the largest city in each district in southern and northern Ghana. The paper does not address rural–urban migration but instead focuses on the livelihoods of rural households. In contrast to the extensive literature focusing on the effects of urbanization on individuals, we assess its impacts on individual rural households as a whole, with a particular focus on youth-headed households. Many rural households have shifted their primary employment from agriculture to nonagriculture, especially in the more urbanized South. In contrast, change in livelihood diversification within rural households with family members’ primary employment in both agriculture and nonagriculture appears much less rapid. Rural youth-headed households are significantly more associated with the transition away from agriculture than households headed by other adults, and such trends are stronger in locations closer to larger cities, particularly in the South. Although the nonagricultural economy is becoming increasingly important for rural households, contrary to expectations, the probit model analysis in this paper shows that agricultural production does not appear to be more intensified—in terms of modern input use—in the more urbanized South, and youth do not show greater agricultural technology adoption than other adults, indicating that the constraints against modern input adoption may be binding for all farmers, including youth and farmers in more urbanized locations. We also find that rural poverty rates are consistently lower among nonagricultural households, and the share of middle-class population is also disproportionally higher among rural nonagricultural households than agricultural households. While the probit analysis confirms the positive relationship between being a nonagricultural household and being nonpoor or becoming middle class after controlling for all other factors, education seems to play the biggest role. As rural youth become more educated and more households shift from agriculture to the rural nonfarm economy, a different range of technologies for agricultural intensification is necessary for agriculture to be attractive for youth. A territorial approach and related policies that integrate secondary cities and small towns with the rural economy deserve more attention such that the diversification of rural livelihoods can become a viable alternative or complement to rural–urban migration for youth.

Height-for-age z-scores (HAZs) and stunting status (HAZ<−2) are widely used to measure child nutrition and population health. However, accurate measurement of age is nontrivial in populations with low levels of literacy and numeracy, limited use of formal birth records, and weak cultural norms surrounding birthdays and calendar use. In this paper we use Demographic and Health Surveys data from 62 countries over the period 1990–2014 to describe two statistical artifacts indicative of misreporting of age. The first artifact consists of lower HAZs for children reported to be born earlier in each calendar year (resulting in implausibly large HAZ gaps between January- and December-born children), which is consistent with some degree of randomness in month of birth reporting. The second artifact consists of lower HAZs for children with a reported age just below a round age (and hence implausibly large HAZ gaps between children with reported ages just below and just above round ages), which is consistent with survey respondents rounding ages down more than they round ages up. Using simulations, we show how these forms of misreporting child age can replicate observed patterns in the data, and that they have small impacts on estimated rates of stunting but important implications for research that relies on birth timing to identify exposure to various risks, particularly seasonal shocks. Moreover, the misreporting we identify differs from conventional age-heaping concerns, implying that the metrics described above could constitute useful markers of measurement error in nutrition surveys. Future research should also investigate ways to reduce these errors.

One finds a broad consensus in the literature regarding the lack of good information on trade in Africa, particularly intraregional trade. This paper attempts to identify gaps and remedies in measuring and tracking trade in Africa. We review the major international and regional databases that track trade in Africa, identifying the gaps therein. We also review the studies that have attempted to track informal trade between African countries, and we look at the major ongoing initiatives to track such informal trade. It appears that both international and regional databases suffer from a lack of reporting or from faulty reporting of African trade statistics. Informal trade flows pose an ongoing problem when measuring intraregional trade, although actual border-monitoring initiatives ongoing in selected countries constitute an interesting option for their quantification. When no direct monitoring method is available, estimating gravity equations represents an alternative with which to measure the potential trade between two partner countries, giving us an estimate of missing trade. A final avenue consists of estimating unregistered trade via national accounts data by comparing consumption, production, and declared trade.

While there is a large body of literature on the negative health effects of air pollution, there is much less written about its effects on cognitive performance for the whole population. This paper studies the effects of contemporaneous and cumulative exposure to air pollution on cognitive performance based on a nationally representative survey in China. By merging a longitudinal sample at the individual level with local air-quality data according to the exact dates and counties of interviews, we find that contemporaneous and cumulative exposure to air pollution impedes both verbal and math scores of survey subjects. Interestingly, the negative effect is stronger for men than for women. Specifically, the gender difference is more salient among the old and less educated in both verbal and math tests.

Nutrition in the Prevention and Treatment of Disease, Fourth Edition, is a compilation of current knowledge in clinical nutrition and an overview of the rationale and science base of its application to practice in the prevention and treatment of disease. In its fourth edition, this text continues the tradition of incorporating new discoveries and methods related to this important area of research Generating and analyzing data that summarize dietary intake and its association with disease are valuable tasks in treating disease and developing disease prevention strategies. Well-founded medical nutrition therapies can minimize disease development and related complications. Providing scientifically sound, creative, and effective nutrition interventions is both challenging and rewarding. - Two new chapters on metabolomics and translational research, which have come to be used in nutrition research in recent years. The new areas of study are discussed with the perspective that the application of the scientific method is by definition an evolutionary process. - A new chapter on Genetics and Diabetes which reviews the latest research on causal genetic variants and biological mechanisms responsible for the disease, and explores potential interactions with environmental factors such as diet and lifestyle. - Includes all major "omics" – the exposome, metabolomics, genomics, and the gut microbiome. - Expands the microbiota portions to reflect complexity of diet on gut microbial ecology, metabolism and health

Understanding how various entities in a policy system at the national level can contribute to improved use of evidence in policy making. Yet little research has focused in developing countries on how various actors and players in a policy system work together to achieve a set of policy goals. In this paper, we study the factors contributing to the effectiveness of a policy system. The process of policy design, adoption, implementation, and refinement requires an effective policy system as well as a capacitated and supportive institutional structure. External actors both through technical and financial assistance often support policy systems in developing countries. Poor coordination and harmonization of such assistance among various actors and players within the country can often result in undermining the very policy systems they try to strengthen. This is typical in the African agricultural development process. In this paper, we develop a conceptual framework for understanding the policy and institutional architecture of food and agriculture policy system and for improving the coordination and harmonization of the roles of policy actors and players. Applying the framework to Ghana, we map and analyze the organizational contributions of various actors and their functional characteristics. We show how such analysis can aid various policy actors in setting priorities and strategies for increasing their capacity and the effectiveness of their roles. Finally, we draw lessons for strengthening the food policy systems in developing countries through effective coordination among local and external actors.