Taylor Vail

Taylor Vail is a researcher with more than 10 years of experience designing, conducting, and managing mixed-methods research and evaluations, primarily in agriculture, food security, nutrition, and public health.

She has led and supported evaluations across Africa, Asia, and Latin America focused on agricultural systems and livelihoods, smallholder resilience, nutrition, health product adoption, and research and innovation portfolios. Her work combines quantitative and qualitative methods to assess program implementation and outcomes and translate findings into action-ready recommendations for funders and implementing partners.

At Mathematica, Vail leads technical work across several large, complex evaluations and research initiatives. She leads qualitative research for a Bill & Melinda Gates Foundation-funded retrospective evaluation examining sustained adoption and disadoption of irrigation technologies among smallholder farmers in Kenya, Ethiopia, and Nigeria. She also provides measurement, learning, and evaluation support to the Foundation’s Nutrition Program Strategy Team within the Global Growth & Opportunity division, helping develop decision frameworks, performance monitoring approaches, and sector-level analyses to inform portfolio and strategy decisions. In addition, Vail leads client exit interview research examining the private-sector scale-up of the self-injectable contraceptive DMPA-SC, integrating discrete choice experiment and willingness-to-pay methods to generate evidence on consumer preferences and inform partners’ demand-generation strategies. For the U.S. Department of Agriculture’s School Nutrition and Meal Cost Study (SNMCS+), she oversees dietary recall data collection and analysis to assess dietary intake patterns among school-age children both in and outside of school.

Before joining Mathematica, Vail served as the senior monitoring, evaluation, and learning lead for One Acre Fund in Tanzania, where she oversaw research and learning activities for programs serving smallholder farmers and managed a field research team of more than 65 staff. She previously led monitoring and evaluation for Semilla Nueva in Guatemala, including developing an ex-ante model to estimate the potential health and nutrition impacts of scaling biofortified maize. Earlier in her career, she worked with the United Nations World Food Programme in Myanmar, where she analyzed post-distribution monitoring data, strengthened nutrition monitoring tools and indicators, and trained implementing partners on data collection and reporting. Her work has been published in journals including Agricultural Systems, Obesity, The American Journal of Clinical Nutrition, American Journal of Health Promotion, and BMC Public Health. She holds an M.S. in Food Policy and Applied Nutrition and an M.P.H. in Epidemiology and Biostatistics from Tufts University, and a B.A. in Biology and Spanish from Bowdoin College.