Pursuing the goals of the Lisbon Strategy, the European Commission addresses the malfunctioning of the Internal Market due to corporate tax obstacles. In this context, effective tax burdens reveal possible distortions of investment decisions. To reduce these distortions the European Commission has, among other proposals, put forward the concept of a Common Consolidated Corporate Tax Base. Against this background, the aim of the study is twofold. One objective is to provide effective tax rates for a wide range of countries (EU 27, Switzerland, Norway, the United States of America, Canada, Japan Croatia, the former Yugoslav Republic of Macedonia and Turkey). The determination of domestic and cross-border effective marginal and average tax rates is based on the approach of Devereux and Griffith. A second objective of the study consists in simulating specific scenarios of corporate taxation in order to assess potential corporate tax reform proposals.