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Agricultural Production, Diets and Health
Friday, Jan. 5, 2018
2:30 PM - 4:30 PM
Agricultural and Applied Economics Association
Michigan State University
Animal Sourced Foods and Child Stunting
Stunting affects 160 million pre-school children around the world, and imposes significant costs on a child’s health, cognitive development, schooling and economic performance. Stunting in early childhood has been linked to poor dietary diversity, notably low intake of animal-sourced foods (ASFs) rich in high quality protein and other growth-stimulating nutrients. Surprisingly, however, very little economic research has focused on ASFs and child growth. In this paper we redress this omission through an analysis of 112,553 children aged 6-23 months from 46 countries. We first document distinctive patterns of ASF consumption among children in different regions, particularly highly variable patterns of dairy consumption, low consumption of eggs and meat, and surprisingly frequent consumption of fish in several poor regions of Africa and Asia. We then examine how ASF consumption is associated with child stunting in multivariate models saturated with control variables. We find strong associations with a generic ASF consumption indicator as well as with fish and dairy consumption. Finally, we explore why ASF consumption is low but also so variable. We show that non-tradable ASFs (fresh milk, eggs) are a very expensive source of calories in low income countries, and that caloric prices of these foods are strongly associated with children’s consumption patterns. A host of other demand-side factors are also important, but the strong influence of prices implies an important role for agricultural policies – in production, marketing and trade – to improve the accessibility and affordability of ASFs in poorer countries.
Technological and Market Interventions for Aflatoxin Control in Ghana
Aflatoxins, carcinogenic secondary metabolites of certain molds, are invisible, tasteless, and odorless and cause serious health problems including liver cancer. Common in ground- nuts and maize, staple foods in much of Africa, aflatoxins pose a major threat to food safety and hinder the development of agricultural value chains. The risk of aflatoxin contamination can be substantially reduced by adopting low-tech, low-cost post-harvest practices. How- ever, these practices are far from universally adopted due to the fact producers do not know about aflatoxins and their effects, and that there are no regulations and little transparency in the informal markets on which most groundnuts are traded. We conducted a randomized control trial in northern Ghana with 1,005 farmers to test three interventions to incite better post harvest practices and reduce aflatoxin levels: (1) information sessions, (2) distribution of free drying tarps, and (3) a price premium for groundnuts tested to be low in aflatoxin. The information session substantially improve post-harvest practices. Tarp receipt further improves some practices, particularly with regards to drying surface. Surprisingly, we find that the price premium had little effect, and few farmers even sold nuts at this premium despite achieving the standard needed to do so. Due to the very low overall levels of aflatoxin throughout Ghana the year of our intervention, we could not detect any effect on aflatoxin levels despite better practices.
The Cost of a (Un)Healthy Diet: Novel Food Price Indexes Based on Nutritional Attributes
Economic index numbers add up prices using weights from observed quantities to reflect producer revenue, market prices or consumers living standards. Standard food price indexes of this type reveal differences and changes in the cost of current dietary patterns, but not whether healthier diets are becoming more or less affordable relative to what is now produced and consumed. Aggregating over the nutritional attributes of different foods to obtain the cost of healthier diets requires a different kind of weighting scheme, to take account of medical or epidemiological information beyond revealed preference. This paper surveys the index number formulas proposed for individual foods such as NuVal scores, for quantities consumed such as a Healthy Eating Index, and for the cost of meeting nutrient needs such as the USDA’s Thrifty Food Plan or similar least-cost diets in developing countries, and we compare these existing measures to new indexes proposed in recent papers for the cost of dietary diversity and the cost of recommended diets. We discuss the price indexes that correspond to each quantity-based measure of diet quality, and provide empirical estimates for these indexes over time and space in various countries around the world.
Robustness and External Validity: What Do We Learn from Repeated Study Designs over Time?
Randomized control trials implemented in particular socio-economic contexts are often criticized as lacking external validity, but the internal validity of studies has also been questioned if season-specific effects influence results. In agricultural and health interventions, this may be particularly true as seasaonlity may affect yields and profits, while in health interventions, particularly those targeted at infectious diseases, weather variability can affect disease incidence in any given year. In pursuing a research agenda to identify the effect of malaria on agricultural worker earnings, labor supply and productivity, our research team has ‘replicated’ our initial study design of offering malaria testing and treatment to piece-rate wage sugarcane cutters (Dillon et al. 2014) in two subsequent agricultural seasons. This paper outlines despite our care in replicating our own study, the potential effects of inherent variations across seasons that re-implementing a study may have on treatment effect estimation. We find significant consistent effects across seasons of the effect of malaria on agricultural earnings, labor supply and productivity, but effect sizes vary depending on season.