In the context of a growing international economic integration, taxation becomes a more and more central factor in the competition of regions and countries for international investment and skilled employees. From that perspective, in addition to the effective level of company taxation also the effective tax burden on highly skilled employees is important: Due to the growing international mobility of highly skilled employees, these employees compare net incomes and force companies to bear international and interregional differences in compensation tax burdens. The present research project will analyze effective tax burdens on corporations and on highly skilled employees in Switzerland for 2026 and 2027. Additionally, it will analyze the effective tax burden in more than 50 different locations from 19 European countries, the U.S. and Asia for 2027. Thereby, it will update and analytically extend the BAK Taxation Index, which has been published first in 2001.