Research Statement
Peer Reviewed Publications
Ryan, Kelsey, Katherine Adams, Stephen Vosti, M. Isabel Odiz, Elizabeth Cimo, and Mark Manary. Forthcoming. “A Comprehensive Linear Programming Tool to Optimize Formulations of Ready-to-Use Therapeutic Foods: An Application to Ethiopia.” American Journal of Clinical Nutrition.
Abstract: Ready-to-use therapeutic food (RUTF) is the standard of care for children suffering from noncomplicated severe acute malnutrition (SAM). The objective of this research was to develop a comprehensive linear programming (LP) tool to create novel RUTF formulations for Ethiopia. A systematic approach that surveyed international and national crop and animal food databases was used to create a global and local candidate ingredient database. The database included information about each ingredient regarding nutrient composition, ingredient category, regional availability, and food safety, processing, and price. An LP tool was then designed to compose novel RUTF formulations. For the example case of Ethiopia, the objective was to minimize the ingredient cost of RUTF; the decision variables were ingredient weights and the extent of use of locally available ingredients, and the constraints were nutritional and product-quality related. Of the new RUTF formulations found by the LP tool for Ethiopia, 32 were predicted to be feasible for creating a paste, and these were prepared in the laboratory. Palatable final formulations contained a variety of ingredients, including fish, different dairy powders, and various seeds, grains, and legumes. Nearly all of the macronutrient values calculated by the LP tool differed by <10% from results produced by laboratory analyses, but the LP tool consistently underestimated total energy. The LP tool can be used to develop new RUTF formulations that make more use of locally available ingredients. This tool has the potential to lead to production of a variety of low-cost RUTF formulations that meet international standards and thereby potentially allow more children to be treated for SAM.
de la Torre, Adela, Arthur Havenner, Katherine Adams, and Justin Ng. 2010. “Premium Sex: Factors Influencing the Negotiated Price of Unprotected Sex by Female Sex Workers in Mexico.” Journal of Applied Economics. XIII(1): 67-90.
Abstract: This paper examines economic, sociocultural, and behavioral risk factors that influence the compensating price difference (premium paid) between sex with and without a condom for female sex workers (FSWs) in U.S.-Mexico border cities. Field data collected in Ciudad Juarez on the price of sex with and without a condom for the same FSW respondent allowed calculation of the price premium for unprotected sex based on these paired prices, holding unobservable characteristics constant. A Tobit model was used to identify the factors determining the price premium. Key predictors of a larger price premium for sex without a condom included: length of time as a FSW; number of male clients; and participation in HIV education. Key predictors of a decrease in the price premium for unprotected sex included: age; a bad financial situation; frequent alcohol consumption before or during sex; and frequent drug use before or during sex.
Working Papers
“Intrahousehold Effects of a Targeted Maternal and Child Nutrition Intervention: Household Behavior and Spillovers in Ghana.” (Job market paper)
Abstract: It is common for health and nutrition interventions to target specific members within a household and for evaluations of their effects to focus exclusively on those members. If a targeted intervention introduces a change to a household’s utility maximization problem (new information, changes in constraints or prices, etc.) or influences decision-making, households might respond to the intervention in ways that affect the well-being of non-targeted members. In this paper we evaluate household behavioral responses to small-quantity lipid-based nutrient supplements (SQ-LNS) provided specifically to mothers and their infants to prevent undernutrition. We find households responded to the randomized, targeted intervention by increasing their labor supply, particularly among fathers, to fund increased expenditures on food (including nutrient-dense foods like fish, milk, and vegetables) and non-food items. Given higher food expenditures, we then explore whether there was an intrahousehold spillover effect on the nutritional status of non-targeted young children in the household. Overall, the nutritional status of these children was unaffected, but we find evidence of an improvement in linear growth among non-targeted children with relatively taller mothers. Taken together, these findings have potentially valuable policy implications for a country like Ghana that is undergoing a nutrition transition and facing the double burden of undernutrition and growing rates of overweight and obesity. More broadly, our findings underscore the value in collecting sufficient data to rigorously evaluate how households respond to targeted interventions and whether those responses generate intrahousehold spillovers.
Adams, Katherine, Travis Lybbert, Stephen Vosti, and Emmanuel Ayifah. “Using Experimental Auctions to Estimate Willingness-to-Pay for a New Maternal Nutrient Supplement in Ghana.”
Abstract: Scaling up access to supplements designed to prevent undernutrition, such as new lipid-based nutrient supplements (LNS), may require both public channels and retail markets. The viability of LNS retail markets will hinge on demand. We use experimental auctions to characterize willingness-to-pay (WTP) for a maternal LNS product in Ghana. WTP is positive for most participants, though below the estimated cost of production for many. WTP varies depending on income, assets, and parity status; information about the long-term benefits of preventing undernutrition has no effect on WTP. These findings have implications for designing public health policy and hybrid public-private delivery mechanisms.
Lybbert, Travis, Stephen Vosti, Katherine Adams, and Rosemonde Guissou. “Experimental Markets for Micronutrient Supplements to Prevent Undernutrition: Estimating Household Demand Persistence in Rural Burkina Faso.”
Abstract: The success of Plumpy’Nut® in treating severe acute malnutrition revolutionized the treatment of malnutrition and sparked efforts to develop similar Lipid-based Nutrient Supplement (LNS) and other products aimed at preventing undernutrition. The move from therapeutic to preventative LNS products has fundamental implications for supply chains and implies that private demand and the private sector will play central roles in the distribution of these products. We use experimental markets in rural Burkina Faso to shed light on household demand for preventative LNS and explore associated product distribution challenges. We conducted experimental auctions for a ‘small quantity’ (SQ) LNS product to gauge initial demand. Then, in collaboration with local vendors, we conducted a year-long market trial in 14 villages that enabled us to test the effect of both price and non-price factors on persistent demand. We find that price elasticity of demand for these supplements is high on average (-5), but that persistent demand is significantly more price sensitive (-8) than first-time purchases (-2.4). We also find that a loyalty card that offers a small reward for a month of purchases may boost persistent demand more effectively than direct price subsidies. Both the price and non-price demand effects diminish after a few months. Even when SQ-LNS products or other micronutrient products are as cost-effective as a nutritional investment, our results suggest that private demand may cover less than half the production and distribution costs, underscoring the need for hybrid private-public delivery strategies. The public sector and private firms – including multinationals in the thriving food and beverage sector in Africa – have complementary competencies that must be leveraged to meet the delivery challenges this paper explores.
Other Publications
Colby, Bonnie G, Elizabeth Basta, and Katie Adams. 2011. “Negotiated Water Transactions and Climate Change Adaptation.” In Colby, Bonnie G. and George Frisvold (Eds), Adaptation and Resilience: The Economics of Climate, Water, and Energy Challenges in the American Southwest. Resources for the Future Water Policy Series.
Colby, Bonnie G, Lena Jones, and Katie Adams. 2011. “Economic Tools For Climate Adaptation: Water Transaction Price Negotiations.” In Colby, Bonnie G. and George Frisvold (Eds), Adaptation and Resilience: The Economics of Climate, Water, and Energy Challenges in the American Southwest. Resources for the Future Water Policy Series.
Colby, Bonnie G., Katie Pittenger Adams, and Dana Smith. 2007. “Water Transactions and Flexibility During Drought.” In Colby, Bonnie G and Katharine Jacobs (Eds), Water Management Innovations for Arid Regions: Arizona Policy and Practice. Resources for the Future Book Series: Issues in Water Resource Policy.
Peer Reviewed Publications
Ryan, Kelsey, Katherine Adams, Stephen Vosti, M. Isabel Odiz, Elizabeth Cimo, and Mark Manary. Forthcoming. “A Comprehensive Linear Programming Tool to Optimize Formulations of Ready-to-Use Therapeutic Foods: An Application to Ethiopia.” American Journal of Clinical Nutrition.
Abstract: Ready-to-use therapeutic food (RUTF) is the standard of care for children suffering from noncomplicated severe acute malnutrition (SAM). The objective of this research was to develop a comprehensive linear programming (LP) tool to create novel RUTF formulations for Ethiopia. A systematic approach that surveyed international and national crop and animal food databases was used to create a global and local candidate ingredient database. The database included information about each ingredient regarding nutrient composition, ingredient category, regional availability, and food safety, processing, and price. An LP tool was then designed to compose novel RUTF formulations. For the example case of Ethiopia, the objective was to minimize the ingredient cost of RUTF; the decision variables were ingredient weights and the extent of use of locally available ingredients, and the constraints were nutritional and product-quality related. Of the new RUTF formulations found by the LP tool for Ethiopia, 32 were predicted to be feasible for creating a paste, and these were prepared in the laboratory. Palatable final formulations contained a variety of ingredients, including fish, different dairy powders, and various seeds, grains, and legumes. Nearly all of the macronutrient values calculated by the LP tool differed by <10% from results produced by laboratory analyses, but the LP tool consistently underestimated total energy. The LP tool can be used to develop new RUTF formulations that make more use of locally available ingredients. This tool has the potential to lead to production of a variety of low-cost RUTF formulations that meet international standards and thereby potentially allow more children to be treated for SAM.
de la Torre, Adela, Arthur Havenner, Katherine Adams, and Justin Ng. 2010. “Premium Sex: Factors Influencing the Negotiated Price of Unprotected Sex by Female Sex Workers in Mexico.” Journal of Applied Economics. XIII(1): 67-90.
Abstract: This paper examines economic, sociocultural, and behavioral risk factors that influence the compensating price difference (premium paid) between sex with and without a condom for female sex workers (FSWs) in U.S.-Mexico border cities. Field data collected in Ciudad Juarez on the price of sex with and without a condom for the same FSW respondent allowed calculation of the price premium for unprotected sex based on these paired prices, holding unobservable characteristics constant. A Tobit model was used to identify the factors determining the price premium. Key predictors of a larger price premium for sex without a condom included: length of time as a FSW; number of male clients; and participation in HIV education. Key predictors of a decrease in the price premium for unprotected sex included: age; a bad financial situation; frequent alcohol consumption before or during sex; and frequent drug use before or during sex.
Working Papers
“Intrahousehold Effects of a Targeted Maternal and Child Nutrition Intervention: Household Behavior and Spillovers in Ghana.” (Job market paper)
Abstract: It is common for health and nutrition interventions to target specific members within a household and for evaluations of their effects to focus exclusively on those members. If a targeted intervention introduces a change to a household’s utility maximization problem (new information, changes in constraints or prices, etc.) or influences decision-making, households might respond to the intervention in ways that affect the well-being of non-targeted members. In this paper we evaluate household behavioral responses to small-quantity lipid-based nutrient supplements (SQ-LNS) provided specifically to mothers and their infants to prevent undernutrition. We find households responded to the randomized, targeted intervention by increasing their labor supply, particularly among fathers, to fund increased expenditures on food (including nutrient-dense foods like fish, milk, and vegetables) and non-food items. Given higher food expenditures, we then explore whether there was an intrahousehold spillover effect on the nutritional status of non-targeted young children in the household. Overall, the nutritional status of these children was unaffected, but we find evidence of an improvement in linear growth among non-targeted children with relatively taller mothers. Taken together, these findings have potentially valuable policy implications for a country like Ghana that is undergoing a nutrition transition and facing the double burden of undernutrition and growing rates of overweight and obesity. More broadly, our findings underscore the value in collecting sufficient data to rigorously evaluate how households respond to targeted interventions and whether those responses generate intrahousehold spillovers.
Adams, Katherine, Travis Lybbert, Stephen Vosti, and Emmanuel Ayifah. “Using Experimental Auctions to Estimate Willingness-to-Pay for a New Maternal Nutrient Supplement in Ghana.”
Abstract: Scaling up access to supplements designed to prevent undernutrition, such as new lipid-based nutrient supplements (LNS), may require both public channels and retail markets. The viability of LNS retail markets will hinge on demand. We use experimental auctions to characterize willingness-to-pay (WTP) for a maternal LNS product in Ghana. WTP is positive for most participants, though below the estimated cost of production for many. WTP varies depending on income, assets, and parity status; information about the long-term benefits of preventing undernutrition has no effect on WTP. These findings have implications for designing public health policy and hybrid public-private delivery mechanisms.
Lybbert, Travis, Stephen Vosti, Katherine Adams, and Rosemonde Guissou. “Experimental Markets for Micronutrient Supplements to Prevent Undernutrition: Estimating Household Demand Persistence in Rural Burkina Faso.”
Abstract: The success of Plumpy’Nut® in treating severe acute malnutrition revolutionized the treatment of malnutrition and sparked efforts to develop similar Lipid-based Nutrient Supplement (LNS) and other products aimed at preventing undernutrition. The move from therapeutic to preventative LNS products has fundamental implications for supply chains and implies that private demand and the private sector will play central roles in the distribution of these products. We use experimental markets in rural Burkina Faso to shed light on household demand for preventative LNS and explore associated product distribution challenges. We conducted experimental auctions for a ‘small quantity’ (SQ) LNS product to gauge initial demand. Then, in collaboration with local vendors, we conducted a year-long market trial in 14 villages that enabled us to test the effect of both price and non-price factors on persistent demand. We find that price elasticity of demand for these supplements is high on average (-5), but that persistent demand is significantly more price sensitive (-8) than first-time purchases (-2.4). We also find that a loyalty card that offers a small reward for a month of purchases may boost persistent demand more effectively than direct price subsidies. Both the price and non-price demand effects diminish after a few months. Even when SQ-LNS products or other micronutrient products are as cost-effective as a nutritional investment, our results suggest that private demand may cover less than half the production and distribution costs, underscoring the need for hybrid private-public delivery strategies. The public sector and private firms – including multinationals in the thriving food and beverage sector in Africa – have complementary competencies that must be leveraged to meet the delivery challenges this paper explores.
Other Publications
Colby, Bonnie G, Elizabeth Basta, and Katie Adams. 2011. “Negotiated Water Transactions and Climate Change Adaptation.” In Colby, Bonnie G. and George Frisvold (Eds), Adaptation and Resilience: The Economics of Climate, Water, and Energy Challenges in the American Southwest. Resources for the Future Water Policy Series.
Colby, Bonnie G, Lena Jones, and Katie Adams. 2011. “Economic Tools For Climate Adaptation: Water Transaction Price Negotiations.” In Colby, Bonnie G. and George Frisvold (Eds), Adaptation and Resilience: The Economics of Climate, Water, and Energy Challenges in the American Southwest. Resources for the Future Water Policy Series.
Colby, Bonnie G., Katie Pittenger Adams, and Dana Smith. 2007. “Water Transactions and Flexibility During Drought.” In Colby, Bonnie G and Katharine Jacobs (Eds), Water Management Innovations for Arid Regions: Arizona Policy and Practice. Resources for the Future Book Series: Issues in Water Resource Policy.