Bringing together top international researchers this book provides a worldwide coverage of underground economic activities. It presents estimates of the underground economy for 145 countries - the most comprehensive ever undertaken; an in-depth examination of the underground economy for a select number of these countries; and an analysis of the public policy implications through an assessment of how various governments have attempted to address this issue. The book brings together the latest research on tax evasion, tax morale and other underlying factors that have so significantly influenced participation in the underground economy. It provides a comprehensive overview of the size and development of the underground economy, its major causes and motivations and its effects on the legitimate economy. In addition, it reviews recent public policy concerns by a number of countries and how they have responded with measures to curb these underground economic activities.