Revision with unchanged content. Many European countries have experienced a significant increase of unemployment in recent years. This publication reviews several theoretical models that try to explain this phenomenon. Predominantly, these models claim a link between the poor performance of European labor markets and the high level of market regulation. Commonly referred to as the Eurosclerosis debate, prominent approaches consider insider-outsider relationships, search-models, and the influence of hiring and firing costs on equilibrium employment. The publication presents empirical evidence of each model and studies the relevance of the identified rigidities as a determinant of high unemployment in Europe. Furthermore, a case study analyzes high unemployment rates in Germany and critically discusses recent reform efforts. This study provides a sober and unprejudiced analysis of the European labor market and its weaknesses. According to the author's convincing argument, substantial efforts are still needed in the areas of institutional reform and incentive-based labor market policy. The book is a must read for political and economic decision-makers. Prof. Dr. Klaus F. Zimmermann; Director; Institute for the Study of Labor (IZA), Germany.