Greenfield has been involved with studies of the US geospatial intelligence workforce; the science, technology, engineering, and mathematics (STEM) workforce in the US Department of Defense and defense industrial base; and the US energy and mining workforce. She is also a principal at Mercer, where she has more than 10 years of experience helping organizations improve the management of their human capital. Recent projects include diversity-related analyses of pay for a professional services organization and a hospital system to identify areas of these organizations with systemic pay disparities, and the generation of diversity benchmarks for four occupations in 18 countries for an international equipment manufacturer. Before joining Mercer, she was an assistant professor of economics at the College of Wooster. She received a PhD in economics from Claremont Graduate University and a BA in business economics from the University of California, Santa Barbara.