This groundbreaking book analyzes how the ecology of taxation is fundamental for the success or failure of tax systems. It specifically focuses on the role of the ecological environment on taxation; the factors that determine the ecology of taxation; and how the ecology of taxation has changed and may continue to evolve. Income taxes operate well in highly industrialized countries, characterized by large enterprises, modern accounting, thousands of workers and tangible products. There are great difficulties, however, when they operate in countries with higher levels of informality. Vito Tanzi addresses this effect and the influence of economic structure; the income distribution; globalization; technology; and various other main elements that determine the ecology of taxation. The implicit, important conclusion is that there are no permanent or universal optimal tax theories: all theories are related to this ecology. Students of taxation from various fields and economists interested in taxation and public finance will appreciate this book's new perspective on success and failure of taxes and tax systems. It will also serve as a useful resource for tax historians, policy experts, teachers, and tax theorists.