This Part provides unique information for each of the OECD countries on the income taxes paid by workers, their social security contributions, the family benefits they receive in the form of cash transfers as well as the social security contributions and payroll taxes paid by their employers. Results reported include the marginal and average tax burden for eight different family types. These data are widely used in academic research and in the formulation and evaluation of social and economic policies. The taxpayer specific detail in this Report enables it to complement the information provided annually in the Revenue Statistics, a publication providing internationally comparative data on tax levels and tax structures in its the thirty member countries. This Part provides detailed results for 2006, definitive results for 2005 and discusses the changes between 2005 and 2006.