Agency Biographies

Dr. Spiro Stefanou is the Acting Deputy Under Secretary for the Research, Education, and Economics mission area, comprised of more than 8,500 employees across five organizations including the Agricultural Research Service, Economic Research Service, National Agricultural Statistics Service, National Institute of Food and Agriculture, and the Office of the Chief Scientist. Together, these organizations advance agricultural research, innovation, data, and Extension addressing agriculture’s highest priorities across the entire U.S. food supply chain.

Since 2020, Dr. Stefanou has served as the Administrator of USDA’s Economic Research Service, providing leadership for this Federal statistical agency’s research, analytical, and technical operations. He oversees professional staff that focus on relevant and timely research and analyses on the economics of agriculture, food, the environment, and rural America. 

Prior to that, he was a Professor of Economics in the Food and Resource Economics Department at the University of Florida and a Professor of Agricultural Economics at Penn State University. 

He is a Distinguished Fellow of the Agricultural and Applied Economics Association and was a Marie Curie Senior Fellow at the University of Crete (Rethymnon, Greece), Mansholt Senior Fellow at Wageningen University (Netherlands), and Jean Monnet Fellow at the European University Institute (Florence, Italy). He has been a visiting professor at the Institute for Advanced Studies (Vienna, Austria), and the Mediterranean Agronomic Institute (at Chania).  Dr. Stefanou has served on the editorial boards of six national and international journals. 

Dr. Stefanou received his Ph.D. in Agricultural Economics from the University of California, Davis, his M.S. in Agricultural and Resource Economics from the University of Maryland and a Bachelor of Arts in Anthropology from George Washington University.

Mr. Joon Park was named as the Agricultural Research Service (ARS) Acting Administrator in March 2025. As Acting Administrator, Mr. Park leads the men and women of ARS in delivering scientific solutions to national and global agricultural challenges through scientific excellence. Before being named Acting Administrator, Mr. Park served as ARS Associate Administrator for Research Operations & Management where he was responsible for the day-to-day operations of both headquarters and the 95 field research laboratories that are organized into 5 regional areas. Prior to this role, Mr. Park served as the Research, Education and Economics (REE) Mission Area Chief Operating Officer (COO) and the ARS Deputy Administrator for Administrative & Financial Management (AFM) where he was responsible for human resources, financial management, agreements, travel, facilities engineering, safety, acquisition, property, homeland security and information technology.

Mr. Park has held other positions with the USDA ARS to include serving as the ARS Human Resources Director and as the ARS South Atlantic Area Deputy Area Director for Business Management. Mr. Park began his Federal career with the Naval Air Systems Command in Patuxent River, MD through the Acquisition Intern Program in 1996 and served in various Logistics Management positions through 2007 when he served as the Director of Logistics for the Navy H-60 Multi-Mission Helicopter Program.

Mr. Park received a Presidential Rank Award as Meritorious Executive in 2022. He graduated from Liberty University in 1996 with a B.S. degree in Government and received his Master of Business Administration (MBA) from The Johns Hopkins University in 2002. In addition, Mr. Park is a graduate of the Federal Executive Institute in Charlottesville, VA, the National Security Studies Program at the George Washington University in Washington, D.C, the Key Executive Leadership Certificate Program at the American University in Washington D.C, and the USDA Senior Executive Service Candidate Development Program (SESCDP).

Dr. Kelly Maguire is the Acting Administrator for the Economic Research Service (ERS), providing leadership and guidance for the agency’s research, analytical, and technical operations. She previously served as the Assistant Administrator for ERS and, prior to that, as the Chief of the Conservation and Environment Branch in the Resource and Rural Economics Division, where she managed a suite of research focused on domestic conservation; natural resources, environment, and agricultural systems; and organic agriculture, as well as data collection and modeling work.

Dr. Maguire joined ERS in April 2018, having previously spent almost 19 years as an Economist at the U.S. Environmental Protection Agency’s National Center for Environmental Economics, where she conducted research and provided technical expertise on a broad range of regulatory actions. In addition, she wrote guidance documents on conducting environmental justice analysis and valuing reductions in environmental and health risks. Her research and expertise include non-market valuation of ecosystem services and health impacts, distributional analysis of environmental impacts, and benefit-cost analysis. Dr. Maguire received a Ph.D. in Economics from Georgia State University and a B.A. in Economics and Political Science from the University of Rochester.

Joseph L. Parsons is the Administrator of USDA’s National Agricultural Statistics Service.

Mr. Parsons leads NASS to provide the agricultural statistics that form a comprehensive, timely and accurate picture of US agriculture. The Agency’s portfolio of reports encompasses more than 400 releases each year in addition to the Census of Agriculture conducted every five years. Parsons works with the NASS Senior Executive Team to improve and enhance the agency’s statistical programs serving all stakeholders while working to ensure NASS is an exemplary employer.

Since beginning his federal career in 1985, Parsons has held various roles and responsibilities at NASS. Prior to his appointment as Administrator, Parsons served as Associate Administrator with responsibility for the oversight and coordination of agency operations and statistical programs. Parsons other senior executive roles include serving as chair of USDA’s Agricultural Statistics Board and director of the NASS Methodology Division as well as serving as NASS Chief Information Officer. Parsons’ service has also included serving as chief data officer, senior research statistician, and providing leadership in multiple field offices.

Parsons was appointed to the Senior Executive Service in 2011 after completing USDA’s Senior Executive Candidate Development Program and American University’s Key Executive Leadership Certificate Program. As part of his leadership training, he served a detail as visiting executive at Statistics Canada.

Parsons graduated from the University of Missouri-Columbia with honors in Agricultural Economics and earned a master’s degree from the University of Maryland-College Park in Survey Methodology. He grew up on the family dairy farm in southwestern Missouri and worked on several farming operations throughout high school and college.

Dr. Jaye L. Hamby is the director of the U.S. Department of Agriculture’s National Institute of Food and Agriculture, the extramural funding agency in the USDA Research, Education and Economics Mission Area. 

USDA NIFA leads and administers an extensive portfolio of about 70 Congressionally authorized and funded programs to provide grant opportunities for universities, research institutions and small businesses. NIFA-funded projects support research, Cooperative Extension, outreach and education projects that drive innovation and prosperity across the U.S. agricultural enterprise. 

Prior to joining USDA NIFA, Dr. Hamby led and directed hundreds of proprietary research efforts, specializing in concept testing, product marketing, value driver analysis, and farm demographic trends. His consultative expertise includes the agronomy, livestock, and farm machinery markets. He has assisted with the launch of numerous crop protection products and authored field sales and competitive positioning manuals. 

Dr. Hamby, a Tennessee native, graduated from the University of Tennessee’s College of Agriculture with a Bachelor of Science degree in Agricultural Education and was honored as the college’s top graduate. Following his selection as a Harry S. Truman Scholar, he attended Oklahoma State University and earned master's and doctorate degrees in Agricultural Education with a specialization in Agricultural Economics. He was an active 4-H’er and a national FFA officer. 

Dr. Jaye L. Hamby was sworn in as the USDA NIFA Director on March 25, 2025. 

Dr. Deirdra Chester serves as the Director of the Office of the Chief Scientist (OCS). In this role, she leads OCS in delivering science and research that undergirds the policies and practices of USDA and its customers and stakeholders. Additionally, she steers collaboration activities for USDA science programs that support scientific excellence, innovation, and capacity to achieve the Department’s mission. Prior to this role, Dr. Chester was with the National Institute of Food and Agriculture (NIFA) were she served as the Division Director for the Division of Nutrition. In this role, she provided leadership and oversight for the Division’s research, education, and Extension activities across the nation through competitive grant programs.

Previously, Dr. Chester was the agency Science Advisor for USDA’s Animal and Plant Health Inspection Service (APHIS). Before APHIS, she served as the National Program Leader for NIFA’s Applied Nutrition Research in the Division of Nutrition. Prior to joining NIFA, Dr. Chester was a scientist at USDA’s Agricultural Research Service.

Additionally, Dr. Chester is a Registered Dietitian/Nutritionist. She has spoken both nationally and internationally on nutrition topics and is on the editorial board of the Journal of Obesity and Chronic Disease.

Dr. Chester is an American University Key Executive Leadership program graduate and is SES certified through the USDA Senior Executive Service Candidate Development Program. Dr. Chester holds a Ph.D. in Nutrition from Florida International University, where she was awarded the McKnight Doctoral Fellowship and was in the inaugural class of the Gates Millennial Scholars. She also holds a master’s degree in food and nutrition science and a bachelor’s degree in nutrition and dietetics from Florida State University.

Dr. Chester is the recipient of numerous honors and awards. The American Public Health Association Food and Nutrition Section awarded her the Mary C. Egan Award and she was recognized by Florida State University’s College of Human Science with the Circle of Excellence Alumni Award.