Our small book presents areport which has been prepared in the year 2000 for the Taxation and Custorns Union Directorate General of the European Commission, under contract no. T AXUD / 00 / 312. Some of the results form part of the report "Company Taxation in the Internal Market" of the Commission Services released in autumn 2001. We present estimates of effective average tax rates (EATR) in five EU Member States (France, Germany, Ireland, the Netherlands and the UK) plus the USA based on the European Tax Analyzer approach. The European Tax Analyzer is a computer based model firm approach for the computation and comparison of international company tax burdens. It has been developed in co-operation with the Centre for European Economic Research (ZEW). We would like to thank the ZEW for this co-operation. Furthermore, we gratefully acknowledge the help and advice of Gerd Gutekunst, Rieo A. Hermann and Thorsten Stetter in preparing the report. Special mention must be made of Gerd Gutekunst, who was also responsible for preparing the printed version of this report.