Stefano Pagiola is an economist in the World Bank's Environment Department. He leads the Bank's work on payments for environmental services. He has worked extensively on economic valuation of environmental and natural resource problems, with particular emphasis on land degradation, ecosystem services, and biodiversity conservation. He joined the World Bank as a Young Professional in 1994. Before joining the Bank, he taught economics at Stanford University and was a Research Associate at Washington State University. He holds a Ph.D. and master’s degree from Stanford University and a bachelor’s degree from Princeton University. His recent publications include a volume of case studies of market-based mechanisms for forest conservation, Selling Forest Environmental Services.