The services sector plays a vital infrastructure role in national economies, employs more people than other sectors, and is the most dynamic sector of world trade. New negotiations under the WTO General Agreement on Trade in Services, which began in January 2000, offer an important opportunity to reap the benefits of greater openness in services markets worldwide. The papers in this volume, produced as part of the OECD Trade Directorate's services project, explore fundamental issues for the services negotiations: what are the barriers to trade in services? How can those barriers be addressed in negotiations to ensure meaningful results? How can services liberalisation be bolstered and underpinned by improved regulatory transparency? Ranging from the incidence and impact of economic needs tests, through quantitative and qualitative formulas for reducing the barriers to trade in services, to possible disciplines affording interested parties the opportunity to comment before regulations are enacted, this volume identifies and analyses innovative solutions to the challenges facing services negotiators.