Optimal International Group

Optimal's International Group (IG) provides rigorous research and analysis to enhance evidence-based decision making in the international development and public policy disciplines.  Optimal's IG team consists of policy analysts, economists, statisticians, evaluation, and information technology specialists.  Projects by the International Group cover a range of economic development issues including education, public health, entrepreneurship, export promotion, agriculture, and food security globally. Our team has experience working globally in these topic areas and collaborating with culturally diverse groups, reflecting Optimal's own diversity. The IG team includes members from all broad subgroups and from five continents, and is proficient in 15 languages, allowing the staff to engage with a range of community groups in demanding situations that require effective communication.

Subject Matter Expertise

  • Economic development
  • Education
  • Public health
  • Information technology
  • Agriculture
  • Nutrition and food security


Technical Expertise:

  • Quantitative and qualitative analysis
  • Econometrics
  • Evaluation methodologies
  • Cost-benefit and cost-effectiveness analysis
  • Collecting and analyzing data
  • Capacity building and training
  • Implementing innovative as well as traditional evaluation processes
  • Developing comprehensive and user-friendly reports


Senior Staff

Mark Turner, PhD (Chief of Party, Economist)

Dr. Mark Turner, a labor economist, has over 20 years of experience in conceptualizing research studies and conducting policy research and empirical studies, as well as bringing the necessary management expertise to lead a large-scale multi-site study. He has either led or overseen the design and implementation of over 50 evaluations. For instance, Dr. Turner is currently the Chief of Party for USAID's Learning, Analysis, and Evaluation Project that is evaluating economic growth activities in 18 countries. He is also the Project Director of the Small Business Administrations' Innovative Economies Support Services Contract where he oversees the evaluation design for analyzing the economic impact of ten regional innovation clusters. He has authored more than 20 reports and publications, several in peer-reviewed journals. Dr. Turner earned a B.A. in economics from Michigan State University, and a Ph.D. in economics from the University of Maryland.

Christabel Dadzie, M.I.A. (Practice Manager, Africa)

Ms. Christabel Dadzie is the Practice Manager for the International Group at Optimal. In this capacity, she ensures that all projects are run smoothly, and also participates in business development activities for this center. She has subject-matter expertise in economic development, particularly education policy and gender studies and has conducted both qualitative and quantitative program monitoring and evaluation, data collection and analysis, and project management and design. Ms. Dadzie is also currently the project manager for the USAID Learning, Evaluation and Analysis Project, where she provides oversight for the implementation of successful evaluations for USAID economic growth programs. Ms. Dadzie has also led independent evaluations in Zambia and the UNDP economist program in Ethiopia, as well as gender and economic analysis for FAO Regional Office for Africa and UN Women, Ghana. She has worked in several African countries including Ethiopia, Liberia, Malawi, Uganda, Rwanda, Ghana, and Zambia.

Claudia Martinez, PhD (Senior Researcher, Latin America and Caribbean)

Dr. Claudia González Martínez is a senior research associate at Optimal. Dr. González Martínez has 10 years of experience working as an economic consultant in the areas of labor and employment, healthcare, international development, and antitrust. She worked as health economist for Population Services International and IMPAQ International. At Optimal she leads evaluation efforts for the USAID Latin America and Caribbean Bureau as part of the USAID LEAP contract.  Dr. González Martínez has extensive knowledge of the Latin American region. A native of Chile who lived in Venezuela for 8 years, Dr. González Martínez has participated in projects in Guatemala, Honduras, Dominican Republic, Puerto Rico, Mexico, and Chile. Dr. González Martínez earned her Ph.D. in economics from the University of Wisconsin, Madison.

Berna Demiralp, PhD (Senior Researcher, Evaluation Design and Entrepreneurship)

Dr. Berna Demiralp is an applied micro-economist with expertise in labor and demographic economics. As a Senior Research Associate at Optimal, she provides critical direction and oversight of projects as well as strategies for mitigating challenges and risks involved in projects. She is currently the project director for the evaluation of Small Business Administration's (SBA) Innovative Economies Initiative, where she leads the evaluation design and contributes to reports for the project. Prior to Optimal, she worked as an Associate Economist at RTI International (formerly Research Triangle Institute). Dr. Demiralp is our resident expert on innovation in entrepreneurship. She earned a PhD in Economics from Johns Hopkins and MA in Economics from Johns Hopkins University.

Neil Bania (Senior Researcher, Economist and Food Security)

Sanford Holman (Operations and Security)

MG Sanford Holman is a combat veteran with 34 years of military and corporate experience, 22 of the years on active duty. He has expertise in strategic planning, operations management, resource allocation, operations research/systems analysis, human resource and logistics management. For example, MG Holman has led a project team in support of Operation Desert Storm tasked with the conduct of modeling, simulation and cost and operational effectiveness analysis. He also led a team involved in human resource modeling and simulation, and a training effectiveness analysis which involved surveys and field data collection as part of the US Army Downsizing in the 1990s. He has worked in the Horn of Africa and Middle East facilitating engineering, health and education projects in support of the State Department, USAID, and Host Nations Ministries. MG Holman lead's our team's operations and security analysis.


U.S. Agency for International Development
U.S. Department of State


Economic Impact of International Exchange Programs
U.S. Department of State, Bureau of Educational and Cultural Affairs

Learning, Evaluation, and Analyst Project (LEAP)
U.S. Agency for International Development, Office of Economic Growth, Education and Environment (E3)