The problems of the modern mixed economy are presented in this book, including general theoretical analyses and applications to specific areas. The subject is treated both mathematically and in a non-technical way.This volume consists of four parts. The papers in Part I are mainly related to the micro-foundations of the mixed economy. The papers in Part II address a number of issues concerning the fundamental properties of the mixed economy. The papers in Part III and IV respectively deal with taxation and public policy evaluation and the role of institutional design. The various articles provide new and stimulating insights in the areas of collective action, economic organization and public sector activities. A few articles contain applications to the Swedish economy.