David Hennessy is Cargill Professor in Economic Systems in the Department of Economics at Iowa State University. His scholarly activities concern the economics of crop and livestock production agriculture including their interfaces with the environment, finance and risk management, food safety and food quality, input markets. His programs emphasize the integration of microeconomic theory with empirics, a systems approach to production, behavioral dimensions to choices, and interdisciplinary collaboration.

Hennessy previously served on faculty at Washington State University and at Michigan State University. He received his Bachelor and Master of Agricultural Science degrees from University College, Dublin, and his PhD in Economics from Iowa State University. Named a Fellow of the Agricultural and Applied Economics Association in 2010, he was co-editor of the American Journal of Agricultural Economics for volumes 93–96 (2011–2014).