Executive Summary -- Aim of the Study -- The Methodology -- Description of Tax and Social Security Systems -- The Effective Tax Burden in the Analysed Countries -- International and Inter-Regional Comparison -- The Importance of Social Security -- Summary and Conclusions.Taxes on the highly skilled are an important cost factor for companies competing internationally for talent. This book provides an international comparison of the effective level of taxes and social security charges imposed on highly qualified employees. Based on a newly developed inter-temporal simulation model, the attractiveness of 7 EU Member States, 12 Swiss cantons, and the United States is assessed. Several compensation packages including old-age provision, fringe benefits, and long-term incentives as well as various income levels and family situations are considered in the analysis. The book also contains a comprehensive survey of social security and tax systems in the countries studied.