In a world where many forms of protection - including tariffs - are constrained by WTO disciplines, non-tariff measures (NTMs) are the new frontier of trade policy. NTMs that are poorly designed or captured by special interests can hurt competitiveness and fragment markets; whereas well-designed ones can effectively overcome informational and other market failures. Assisting governments in the design of NTMs is a critical challenge for donors and development agencies. However, many issues relating, for example, to regional harmonisation and the interaction of NTMs with market structure are still imperfectly understood. This CEPR/World Bank volume brings together recent work by young scholars that draws on original data to shed light on some of the key analytical and policy issues.