Herrington, C. "Does bid quantity matter? Results from a Field Experiment in Zimbabwe" (In preparation)  (Link) 

Abstract: Researcher pre-specified experimental product quantity is the status-quo when conducting willingness-to-pay (WTP) estimates, resting on the assumption of economic rationality. Yet, recent consumer hypothetical studies have found experimental quantity can impact marginal bidding behavior. This study investigates if, and to what degree, varying bid quantity in WTP elicitation impacts marginal WTP via a non-hypothetical field experiment using 527 bean farmers in rural Zimbabwe. Farmers were randomly assigned to either a fixed quantity group (FQG) where farmers bid on a 2kg seed pack or a variable quantity group (VQG) where farmers’ experimental quantity was matched to their intended purchase quantity. Preliminary results find that, on average, marginal WTP is 55% higher in the FQG than the VQG, and increases with highly differentiated bean seeds. We find evidence that this difference in WTP across treatment groups is due to a behavioral bias that can arise from mental budgeting, if intended purchase quantity is above the experimental bid quantity used. These results point to the need for researchers to think critically about the experimental quantity used when designing input-based producer WTP studies, setting the experimental quantity to intended purchase quantity, when possible, to avoid potential overestimation of WTP bids. Differing marginal WTP results from the experimental bid quantity can have major implications to the pricing strategies of agro-dealers, costs to international organizations and NGOs trying to launch a new potentially socially-desirable agricultural input, or the decision for potential government price-level interventions for smallholder farmers. 

Herrington, C. L., Maredia, M. K., Ortega, D. L., Taleon, V., Birol, E., Sarkar, Md. A. R., & Rahaman, Md. S. (2022). “Rural Bangladeshi Consumers’ (Un)Willingness to Pay for Low-milled Rice: Implications for Zinc Biofortification.” Agricultural Economics, 1–18. https://doi.org/10.1111/agec.12739  (Essay 1 of dissertation)

Birol E, Foley J, Herrington C, et al. (2022) “Transforming Nigerian Food Systems Through Their Backbones: Lessons from a Decade of Staple Crop Biofortification Programing.” Food and Nutrition Bulletin. (2022) https://doi.org/10.1177/03795721221117361

Vaiknoras, K., Larochelle, C., Birol, E., Asare-Marfo, D. and C. Herrington. (2019) “The Roles of Formal and Informal Delivery Approaches in Achieving Fast and Sustained Adoption of Biofortified Crops: Learnings from the Iron Bean Delivery Approaches in Rwanda.” Food Policy, 83:271-284, https://doi.org/10.1016/j.foodpol.2018.11.003

Mulambu J., Andersson M., Palenberg M., Pfeiffer W., Saltzman A., Birol E., Oparinde A., Boy E., Herrington C., Asare-Marfo D., Lubobo A., Mukankusi C. and S Nkalubo. “Iron Beans in Rwanda: Crop Development and Delivery Experience.” African Journal of Food, Agriculture, Nutrition and Development 17, no. 2 (2017): 12026-12050. http://www.bioline.org.br/pdf?nd17038

Goeb, J., Maredia, M., Herrington, C., and A.M. Zu. 1.  “Agricultural extension in the times of crisis and emergent threats: Effectiveness of a fall armyworm information intervention in Myanmar.” Myanmar Strategy Support Program Working Paper 36. Washington, DC: International Food Policy Research Institute. https://doi.org/10.2499/p15738coll2.136713 (Submitted)

Abstract: Agricultural extension can have important impacts on vulnerable populations by increasing food production, which improves both rural incomes and urban food security. Mobile phones and digital extension have recently emerged as a low-cost tool to deliver information to farmers. However, different digital extension program designs – the information content, delivery mechanism, and timing – may have differing impacts on farmer knowledge and behavior. Digital extension design may be especially important (i) in the face of new and emergent threats to farm production, and (ii) in crises or violent conflict when trust in outside information is low and conventional extension channels are disrupted. This study uses a randomized controlled trial to test the efficacy of two digital extension designs for delivering fall armyworm information to maize farmers in Myanmar during the dual crises of COVID-19 and a military coup. The first extension design is a direct-to-farmer SMS program. The second is an innovative lead-farmer based digital extension program designed to reach farmers with information through a local, trusted source. We find differential impacts on knowledge, practices, and pest control efficacy relative to the control group and across the two designs. Both programs changed farmer knowledge, but in different areas. The lead farmer design led to increased fall armyworm scouting and control practices, and ultimately to more effective use of pesticides in damage control estimations. Similar cellphone-based lead-farmer programs could be an effective tool for increasing trust in digital extension programs, particularly in fragile states and when faced with emergent threats to agriculture. 

Herrington, C., Birol, E. and K. Lividini. “Global Targeting for Biofortified Crop Interventions.” (In preparation)
Previous version: “Prioritizing Countries for Biofortification Interventions: Biofortification Priority Index Second Edition (BPI 2.0).” HarvestPlus Working Paper No. 40. Washington, DC: International Food Policy Research Institute/HarvestPlus. 

Abstract: Biofortification, a nutrition-sensitive agricultural intervention is one proven solution to address micronutrient deficiency. Biofortification uses conventional plant breeding methods to increase the densities of vitamin A, iron and zinc in staple food crops. To determine where and in which crop-micronutrient combinations to invest, this paper contributes an updated Biofortification Priority Index (BPI) across 128 countries in Africa, Asia, and Latin America and the Caribbean with updated methodology and additional crop-micronutrient combinations. The BPI ranks countries according to their suitability for investment in biofortification inventions to be used by stakeholders with differing objectives. The BPI is calculated based on three subindices: production, consumption, and micronutrient deficiency using country-level data. Results show that Africa and South Asia remain the highest priority regions for the introduction of biofortified crops, globally. Among the primary crops, vitamin A crops are predominately most suitable in Africa south of the Sahara. Irons beans are suitable in Latin America and the Caribbean region, as well as South Asia and Africa south of the Sahara, zinc wheat is predominantly suitable in North Africa and Asia while zinc rice is most suitable in South and Southeast Asia. 

Herrington, C., Maredia, M., Ortega, D., and B. Reyes. "Aspirations and farmer willingness-to-pay for biofortified bean seed: a field experiment in rural Zimbabwe." (Essay 2 of dissertation; Analysis and manuscript in preparation)

Taleon, V.,  Herrington, C., Sarkar, Md. A. R., and Md. S. Rahaman. “Consumer Sensory Evaluation of Selected Rice Varieties and Processing Levels in Bangladesh.” (Analysis and manuscript in preparation)

Lividini, K., Herrington, C., Birol, E. "Farmer adoption of zinc rice in Bangladesh: a nationally-representative study". (Analysis in process)

Kilders, V., Herrington, C., Lusk, J. “Does inflation deflate preferences for individual product attributes? An experimental simulation of consumer preference adjustments in response to price increases.” (Analysis in process)

Herrington, C., Maredia, M., Ortega, D., Reyes, B. "Farmer adoption of biofortified bean seed in Zimbabwe and the role of learning." (Data collected, analysis yet to begin)

Herrington, C., Kilders, V., Lusk, J. “Explaining differences in preferences for food attributes using an altruism index.” (Data collected, analysis yet to begin)

Maredia, M., Ortega, D., Herrington, C. “Economic cost benefit analysis of control methods for Coffee Leaf Rust Disease in Hawaii.” (Data currently being collected)

Larochelle, C., Labarta, R., Katungi, E., Herrington, C., Alwang, J., Asare-Marfo, D., Ball, A. and E. Birol. (2017). “Farming Practices and Crop Varietal Choice among Ugandan Bean and Sweet Potato Producers.” HarvestPlus Research for Action Paper Series 8. Washington, DC: International Food Policy Research Institute/HarvestPlus.

Asare-Marfo, D., C. Herrington, E. Birol et al. (2016a). “Assessing the Adoption of High Iron Bean Varieties and Their Impact on Iron Intakes and Other Livelihood Outcomes in Rwanda: Main Household Survey Report.” Washington, DC. HarvestPlus, International Food Policy Research Institute.

Asare-Marfo, D., C. Herrington, E. Birol et al. (2016b). “Assessing the Adoption of High Iron Bean Varieties and Their Impact on Iron Intakes and Other Livelihood Outcomes in Rwanda: Listing Exercise Report.” Washington, DC. HarvestPlus, International Food Policy Research Institute.

Mulugu, K. and C. Herrington. (2016). “Acceptance and Integration of Biofortified Vitamin A Maize into Common Diets in Northern Zambia.” HarvestPlus Research for Action Paper 6. Washington, DC: International Food Policy Research Institute/HarvestPlus.

C. Herrington. (2014). “A Study of Opportunity International’s Agricultural Programs with an Emphasis on Female Farmers.” Internal Report for Opportunity International – Chicago, IL.

C. Herrington. (2014). “Wami-Dakawa Morogoro Rice Marketing Survey Findings for Opportunity Tanzania Limited” Internal Report for Opportunity International – Chicago, IL.