The study provides a synthesis and analysis of the main types of research on trafficking in different parts of the world, and shows that despite the growing literature on trafficking, relatively few studies are based on extensive or empirical research, and information on the actual numbers of people trafficked remains very sketchy. The book, which includes 9 regional chapters, and 3 chapters dealing with methodological issues, suggests a number of ways in which to enhance research and data on human trafficking, and includes papers by more than a dozen experts. Suggestions include that policy appproaches should become more evidence-based, that more priority be given to evaluation research, and the need to find ways to generate better data and indicators.