The OECD series Illicit Trade provides decision makers with insightful analysis of black and grey markets, as well as innovative guidance and evaluations of policies designed to reduce or deter them. It covers a wide spectrum of studies on illicit market sectors, from counterfeits and narcotics to humans and wildlife, as well as reports on cross-cutting facilitators of illicit trade, such as free trade zones or the use of small parcels to avoid detection. It builds on quantitative analysis and qualitative insights, and benefits from discussions with OECD and non-OECD countries as well as non-government stakeholders.