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With research staff from more than 60 countries, and offices across the globe, IFPRI provides research-based policy solutions to sustainably reduce poverty and end hunger and malnutrition in developing countries.

researcher spotlight

Kate Ambler

Kate Amber is a Senior Research Fellow in the Markets, Trade, and Institutions Unit. Kate’s research broadly focuses on interventions that can increase incomes for smallholders and other microenterprises in agrifood value chains, with a specific focus on the inclusion of women. This includes work on programming in fragile settings, innovations in agricultural finance, and regulatory solutions for food safety. 

Where we work

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IFPRI currently has more than 600 employees working in over 80 countries with a wide range of local, national, and international partners.

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experts

Markets, Trade, and Institutions

Vivian Hoffmann

Senior Research Fellow

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Bio

Vivian Hoffmann is a Senior Research Fellow in the Markets, Trade, and Institutions Unit and an Associate Professor of Economics and Public Policy and Administration at Carleton University in Ottawa, Canada. Much of Hoffmann’s research has focused on two themes: household preventive health behavior and farmer adoption of agricultural technologies. Current projects include randomized evaluations of agronomy training in Uganda, and interventions to improve food safety practices among meat processors and retailers in Kenya, Viet Nam, and Ethiopia. Hoffmann also serves as the Deputy Lead of the CGIAR One Health Initiative. She holds a PhD in Applied Economics from Cornell University.

Publications

CV

Publications

Resource thumbnail

Working Paper

Consumer response to food safety risk information

2024Hoffmann, Vivian; Murphy, Mike; Kariuki, Sarah
Details

Consumer response to food safety risk information

Unsafe food imposes significant health and productivity burdens on developing countries. We test the impact of a simple information intervention through which low-income urban consumers in Kenya were provided information about the likelihood that maize flour from the formal and informal sector violated a food safety standard. We find a 42 percent increase in the share of households consuming the similarly priced, lower risk formal sector flour type at follow-up in the treatment group relative to the control group, from a base of 33 percent. The intervention was equally effective for households earning below and above the sample median income level. Our results demonstrate the potential for low-cost interventions to increase the salience of food safety as a product attribute in informal markets or where regulatory enforcement is weak.

Year published

2024

Authors

Hoffmann, Vivian; Murphy, Mike; Kariuki, Sarah

Citation

Hoffmann, Vivian; Murphy, Mike; and Kariuki, Sarah. 2024. Consumer response to food safety risk information. IFPRI Discussion Paper 2305. Washington, DC: International Food Policy Research Institute.

Keywords

Consumers; Food Safety; Health; Households; Productivity

Language

English

Access/Licence

Open Access

Source

Source record

Project

One Health

Record type

Working Paper

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Working Paper

Effectiveness of aflatoxin biocontrol: Evidence from Kenyan smallholders under varied levels of technical support

2024Kariuki, Sarah W.; Mohamed, Asha B.; Mutuku, Urbanus; Mutegi, Charity; Bandyopadhyay, Ranajit; Hoffmann, Vivian
Details

Effectiveness of aflatoxin biocontrol: Evidence from Kenyan smallholders under varied levels of technical support

Agricultural technologies shown to be highly effective in research trials often have a lower impact when utilized by smallholder farmers. Both heterogeneous returns and suboptimal application are believed to play a role in this efficacy gap. We provide experimental evidence on the impact of a biocontrol product for the control of aflatoxin, a carcinogenic fungal byproduct, as applied by smallholder farmers in Kenya. By varying the level of external support across farmers, we investigate the role of misapplication in the effectiveness gap. We find that the provision of biocontrol together with a one-time training on application reduces aflatoxin contamination in maize relative to a control group by 34 percent. Additional training to the farmers in the form of a call to remind them of the correct time of application in the crop cycle increases the reduction to 52 percent. Our findings indicate that farmers can achieve meaningful improvements in food safety using biocontrol even with minimal training on its use and that additional support at the recommended time of application can strengthen its impact.

Year published

2024

Authors

Kariuki, Sarah W.; Mohamed, Asha B.; Mutuku, Urbanus; Mutegi, Charity; Bandyopadhyay, Ranajit; Hoffmann, Vivian

Citation

Kariuki, Sarah W.; Mohamed, Asha B.; Mutuku, Urbanus; Mutegi, Charity; Bandyopadhyay, Ranajit; and Hoffmann, Vivian. 2014. Effectiveness of aflatoxin biocontrol: Evidence from Kenyan smallholders under varied levels of technical support. IFPRI Discussion Paper 2304. Washington, DC: International Food Policy Research Institute.

Country/Region

Kenya

Keywords

Africa; Eastern Africa; Sub-saharan Africa; Food Safety; Aflatoxins; Impact Assessment; Agricultural Technology; Smallholders; Training; Maize; Crops

Language

English

Access/Licence

Open Access

Source

Source record

Project

One Health

Record type

Working Paper

Resource thumbnail

Journal Article

Self-selection versus population-based sampling for evaluation of an agronomy training program in Uganda

2024Hoffmann, Vivian; Doan, Miki Khanh; Harigaya, Tomoko
Details

Self-selection versus population-based sampling for evaluation of an agronomy training program in Uganda

One of the challenges in evaluating the impact of agronomy training programs, particularly on downstream impacts such as yield, is identifying a sample of farmers who are likely to participate in the training. We assess farmers’ participation in a farm business training activity before the agronomy training intervention as a sample identification mechanism. The screening activity was designed to appeal to the same group of farmers targeted by a coffee agronomy training program, while having minimal impact on the program’s goal of increasing coffee yields. A three-session training on farm business management was conducted in 22 study villages in central Uganda. Coffee agronomy training was then offered in half of these villages, based on random assignment. The results show that 52% of coffee farmers who attended the first business training session subsequently attended agronomy training, compared to 22% of those identified through a census. Applying these results to the design of a large ongoing randomised controlled trial, we find that using a self-selected sample reduces the minimum detectable effect of agronomy training on coffee yield to 15.83%, compared to 38% if population-based sampling were used.

Year published

2024

Authors

Hoffmann, Vivian; Doan, Miki Khanh; Harigaya, Tomoko

Citation

Hoffmann, V., Doan, M.K. and Harigaya, T. Self-selection versus population-based sampling for evaluation of an agronomy training program in Uganda. Journal of Development Effectiveness 16(4): 375-385. https://doi.org/10.1080/19439342.2023.2236080

Country/Region

Uganda

Keywords

Africa; Eastern Africa; Agronomy; Coffee; Capacity Building

Language

English

Access/Licence

Limited Access

Links

https://doi.org/10.1080/19439342.2023.2236080 Source record

Project

One Health

Record type

Journal Article

Blogs

Training Ugandan coffee farmers on agronomy practices more than pays for itself
IFPRI Blog
 | 
August 05, 2024

Training Ugandan coffee farmers on agronomy practices more than pays for itself

By Vivian Hoffmann

Promise for boosting yields and income.

World Food Safety Day 2024: Empowering consumers and small businesses with information
IFPRI Blog
 | 
June 06, 2024

World Food Safety Day 2024: Empowering consumers and small businesses with information

By Vivian Hoffmann

Targeting interventions to benefit public health.

The challenges of influencing consumer behavior to improve food safety
IFPRI Blog
 | 
August 31, 2020

The challenges of influencing consumer behavior to improve food safety

By Vivian Hoffmann and Emily Wu

Two studies in Kenya examine risk perceptions of aflatoxin in maize.

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Events

Implications of El Niño 2023/24 for Africa South of the Sahara
IFPRI Policy Seminar

 | 

November 29, 2023, 7:30 – 9:00 am

Implications of El Niño 2023/24 for Africa South of the Sahara

Virtual Event: November 29, 2023 at 7:30am-9:00am EST. IFPRI in collaboration with USAID FEWS NET and NASA’s Goddard Space Flight Center, is hosting a presentation on the potential impact of the upcoming El Niño on the global agrifood system, with special emphasis on low-income countries in Africa South of the Sahara. The event will be organized around four short talks.

5th Annual Agriculture, Nutrition & Health (ANH) Academy Week
IFPRI Program/Country Event

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June 30 to July 2, 2020

5th Annual Agriculture, Nutrition & Health (ANH) Academy Week

IFPRI is participating in ANH Academy Week that will bring together a community of researchers, practitioners and policymakers from across the world working at the intersection of agriculture, nutrition and health to foster knowledge exchange, innovation and learning, touching on COVID-19’s impacts on our shared work. Presenter(s) Title Date Time John McDermott Welcome Remarks  30-Jun  9:00am John […]

2018 Agricultural & Applied Economics Association (AAEA) Annual Meeting
IFPRI at External Event

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August 5 to 7, 2018

2018 Agricultural & Applied Economics Association (AAEA) Annual Meeting

IFPRI will participate in the 2018 AAEA meeting. The AAEA addresses agricultural economics, international and rural development, and more.

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News

January 13, 2020 | In the News

Kenyans love maize. But aflatoxins are making it dangerous (BMJ Journals)

BMJ Journals reported on the dangers and ways to prevent aflatoxin poisoning. The findings from two IFPRI studies were referenced in the article, the first by Research Fellows Vivian Hoffmann and Jef Leroy and Kelly Jones, The impact of reducing dietary aflatoxin exposure on child linear growth: a cluster randomised controlled trial in Kenya, and […]

November 26, 2019 | In the News

What must be done to get toxin out of Kenya’s food supply (The Conversation)

The Conversation published a Q & A article with Research Fellow Vivian Hoffmann on her insights about aflatoxins, a poisonous, toxic chemical produced by a fungus (Aspergillus flavus). Aflatoxins are found in many of Kenya’s popular maize flour brands. Hoffman discusses how to reduce and eventually eliminate aflatoxins in food and the roles that farmers, […]