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OCE–Immediate Office 
Room 112-A, Whitten Federal Building (mail stop: 3810)
202-720-4164 (Main Line)
202-720-5955 (Main Line)

Shirley E. Brown
Administrative Officer

Shirley E. Brown is a distinguished Administrative Officer with over 37 years of experience with the Federal Government, including 24 years of specialized expertise with the Department of Agriculture (USDA), Office of the Chief Economist (OCE) systems, procedures, and policies. Highly organized, excellent communicator that is driven by results, with a dedicated focus on USDA’s mission and vision. Prior to joining OCE Ms. Brown worked at the USDA, Economic Research Service for 14 years. Ms. Brown has received several diplomas and certificates in the area of Business Administration.

Shawn Arita
Senior Economist

Shawn Arita serves as a Senior Economist in the Office of the Chief Economist at the U.S. Department of Agriculture, Washington DC. In his role he conducts economic analysis and advises the Chief Economist and senior officials regarding the economic effects of various trade policy issues, ongoing events in global commodity markets, and other areas affecting the U.S. farm economy. He performs economic modelling on policy issues of interest for U.S. agriculture and has conducted model-based assessments as needed by USDA programs such as the MFP and CFAP programs as well as arbitration of WTO trade dispute cases. He has published economic research articles in academic journals such as the American Journal of Agricultural Economics, Food Policy, Ecological Economics, Applied Economic Perspectives and Policy, and others. Prior to this position, Shawn was an economist at the Economic Research Service, USDA and also served at the United States Trade Representative (USTR). Shawn received his Ph.D. from the University of Hawaii and originally hails from the Aloha State.

Vincent Breneman
Senior Geographer

Vince Breneman serves as the Senior Geographer in the Office of the Chief Economist (OCE) at the U.S. Department of Agriculture (USDA). He is responsible for geospatial analytics, data development, and data visualization across a range of agricultural and food sector issues with special focus on agricultural programs, markets and natural disasters. Vince joined the OCE in August of 2019. Prior to that, he served as the Chief of the Research Support Branch and Geospatial Program Manager at the Economic Research Service. Vince has MS and BA degrees in Geography from George Mason University and Virginia Tech.

Vanessa Brown-Harrod
Resource Management Analyst (Budget Execution)

Mrs. Brown-Harrod is an Administrative Officer for the Office of the Chief Economist under the Office of Energy and Environmental Policy. Mrs. Brown-Harrod serves as an Administrative Officer responsible for providing budget execution, interagency agreements, cooperative agreements invoicing, purchasing and contract award support to the Office of the Chief Economist and division staff offices. She previously worked for 13 years with USDA, Foreign Agricultural Service serving as a program assistant. Mrs. Brown-Harrod graduated from the University of Maryland Global Campus formerly known as (University of Maryland University College) with a B.S. in Information Technology Services.

Jean Buzby
Food Loss & Waste Liaison

Dr. Jean Buzby has worked at the U.S. Department of Agriculture for over 25 years and is currently the USDA Food Loss and Waste Liaison in the Office of the Chief Economist. Prior to this position, she was on detail at the U.S. Environmental Protection Agency’s Resource Conservation and Sustainability Division as a Senior Policy Analyst. For most of her career, she has worked at USDA’s Economic Research Service (USDA/ERS), first as an Agricultural Economist and then as the Chief of the Diet, Safety, and Health Economics Branch in the Food Economics Division. Prior to moving into management, her primary areas of work were food safety, food consumption, and food loss research. Dr. Buzby's food safety research included estimating the costs of foodborne illness, analyzing the legal incentives for firms to produce safer food, and exploring international trade and food safety issues. Her food consumption research was primarily centered on using information gleaned from the Food Availability (Per Capita) Data System. Dr. Buzby is domestically and internationally known for her estimates of food loss at the retail and consumer levels in the United States. Dr. Buzby received her Ph.D. and M.S. in Agricultural Economics from the University of Kentucky.

Celia Hernandez
Program Management Specialist (Grants)

Ms. Hernandez is a Fellow for the Office of Energy and Environmental Policy. Ms. Hernandez serves as a program assistant, finance liaison, and provides research support to senior Economist. She previously worked for USDA’s Office Program and Budget Analysis. Ms. Hernandez graduated from the University with a B.A. in Economics.

Mary Ellen Mitchell-Whisnant
Chief of Staff

Mary Ellen Mitchell-Whisnant joined the USDA Office of the Chief Economist in 2021. In her role as Chief of Staff, she provides leadership for the day to day operation of OCE in addition to serving as an advisor and coordinator on strategic priorities for the Chief Economist and Deputy Chief Economist. Prior to joining OCE, Mary Ellen was the Acting Director for the Office of Community and Economic Development at the U.S. Treasury Department, where she also served as interim Executive Secretary during the 2017 Presidential Transition. In addition to her time at Treasury, she was also a Federal Financial Management Fellow in the Office of Management and Budget from 2018 to 2019. She began her federal career at the U.S. Environmental Protection Agency (EPA) and is a Returned Peace Corps Volunteer. Mary Ellen holds a BA in International Studies from Allegheny College and an MA, summa cum laude, in Public Management from The Johns Hopkins University.

Rebecca Nemec Boehm
Senior Economist

Rebecca Nemec Boehm is a Senior Economist in the Immediate Office of the Chief Economist. Rebecca has expertise in the economics of food and nutrition assistance programs, nutrition science and policy, food systems, and the environmental dimensions of agricultural production. Prior to joining OCE in 2022, Rebecca was a Senior Economist in the Food and Environment Program at the Union of Concerned Scientists and worked as a Postdoctoral Research Fellow at the University of Connecticut Agricultural and Resource Economics Department and at the UConn Rudd Center for Food Policy and Health. Rebecca received her MS and PhD from the Tufts Friedman School of Nutrition Science and Policy and her BA in Ecology and Evolutionary Biology from Princeton University. Rebecca grew up in California’s Central Valley and served as a research intern at USDA’s Agricultural Research Service research station in Parlier, California in her younger years, collecting soil and water samples from alfalfa fields on the western edge of Fresno County.

Sharon S. Sydow
Senior Economist

Sharon Sydow is a Senior Economist in the Office of the Chief Economist (OCE). In OCE, her focus is on providing economic analysis of agricultural trade policies and market developments. She began her career with the U.S. Department of Agriculture (USDA) in 1991 at the Economic Research Service (ERS), where she was hired as the grains and oilseeds analyst for the Soviet Union. After the breakup of the Soviet Union, her research focused on agricultural trade and policy reform in Russia and other former Soviet countries. In 1998, she moved to USDA’s Foreign Agricultural Service (FAS) to work on multilateral trade negotiations at the World Trade Organization (WTO). In 2001, she was named Director for Agricultural Trade Policy in the Office of the U.S. Trade Representative (USTR), where she worked on a number of bilateral and multilateral agricultural trade issues. After several years of private sector work on agricultural trade issues, she returned to USDA in 2015 to work in OCE. She received her B.A. from Miami University (Ohio) and a Masters in International Affairs from Columbia University, where she also attended the W. Averell Harriman Institute for the Advanced Study of the Soviet Union.