Sahan T. M. Dissanayake is an Associate Professor of Economics and Director of the Institute for Economics and the Environment at Portland State University. He also serves as Undergraduate Committee Chair in the Department of Economics, a Research Advisor for IUCN-Sri Lanka, and an Associate Editor of Environment and Development Economics.

Sahan is an environmental and resource economist who applies economic tools to understand and address environmental challenges. His research focuses on ecosystem services, land and marine conservation, climate change, energy policy, and environmental issues in developing countries. He uses choice experiment surveys to study public preferences and values, spatial optimization models to guide resource allocation, experimental methods to evaluate behavior and policy, and carbon accounting methods to assess environmental impacts. He has published 38 peer-reviewed journal articles and six book chapters, and his work has been cited more than 1,000 times.

His survey research examines preferences for grassland restoration in Illinois, riparian tree shading to improve water quality in Oregon, payments to prevent deforestation (REDD+) in Nepal and Ethiopia, coral reef conservation in Okinawa, sustainable seafood labels in New England, improved cookstove adoption in Ethiopia, and the restoration of ancient irrigation systems in Sri Lanka. He has also studied Indigenous land tenure in Peru and public preferences for a proposed national park in Maine.

Recent projects examine coastal flood adaptation in Oregon, urban greenspace use and environmental justice in Portland, nature prescriptions and health, and the cultural and spiritual values associated with ecosystems. His research also explores the economic impacts of industrial hemp cultivation and shale gas development, industrial decarbonization, and the carbon footprints of industrial hemp and organizations in Oregon.

Sahan’s spatial optimization research examines how to allocate limited resources to achieve conservation and environmental management goals. Applications include conservation planning within U.S. military installations, land conservation under climate change, and post-wildfire land management to protect water quality. His broader modeling work has also explored spatially targeted subsidies for renewable energy, environmental taxation, externalities affecting hydropower, and optimal school districting.

Sahan works closely with communities, practitioners, and public agencies to connect research with environmental decisions. He is leading a U.S. Forest Service-funded participatory research project that combines watershed modeling and spatial optimization to guide post-wildfire land management and protect water quality. He was a co-principal investigator on a NOAA-funded project examining public acceptance of coastal climate adaptation in Oregon. His work with the Natural Resources Council of Maine on preferences for a proposed national park informed efforts to designate the Katahdin Woods and Waters National Monument. His research has received over $1.4 million in grant funding.

His research has also been shared through policy reports, technical publications, and articles for broader audiences. His academic publications have appeared in journals including Land Economics, World Development, Conservation Biology, Urban Forestry & Urban Greening, Ecological Economics, European Journal of Operational Research, Fish and Fisheries, and the Journal of Economic Education. In 2025, he received the Researcher of the Year Award from PSU’s College of Urban and Public Affairs. His other recognitions include PSU’s Roy W. Koch Award for Sustainability Leadership in 2023 and the University of Illinois’s Robert Ferber Dissertation Award for Excellence in Survey Research in 2011.

Sahan regularly engages with policymakers and practitioners through workshops, short courses, and policy publications. He teaches in the Kinship Conservation Fellows summer program and taught in the South Asian Network for Development and Environmental Economics (SANDEE) Summer School in 2024. He was the lead organizer of the 2017 NAREA Workshop on Land Conservation and Climate Change in Washington, D.C., and the faculty lead for the 2019 Conservation Finance Bootcamp at PSU. He has also organized and conducted capacity-building workshops on ecosystem services, biodiversity, and conservation policy in Sri Lanka, Nepal, and Ethiopia. He previously served on the boards of the Forest Park Conservancy and the Natural Resources Council of Maine.

Sahan has taught at Portland State University, Colby College, and the University of Illinois. His courses include graduate and undergraduate microeconomic theory, mathematical economics, environmental and natural resource economics, the economics of ecosystem services and biodiversity, and principles of microeconomics and macroeconomics. His teaching recognitions include the CUPA Outstanding Teacher Award in Economics in 2021, the Louis V. Logeman Graduate Student Teaching Award, and the North American Colleges and Teachers of Agriculture Graduate Student Teaching Award. He was also named to the University of Illinois’s List of Teachers Ranked as Excellent for eight semesters. He is committed to mentoring students and has supported undergraduate and graduate students in presenting at professional conferences and coauthoring peer-reviewed publications.

Sahan received a Ph.D. in Agricultural and Applied Economics (2011) and an M.Sc. in Applied Mathematics (2010) from the University of Illinois, and a B.A., cum laude, in Computer Science and Economics (2004) from Ohio Wesleyan University. He received Ohio Wesleyan’s Young Alumni Award in 2014. Sahan hails from Kandy, Sri Lanka, and enjoys reading, cooking, and eating in his spare time.