This paper presents marginal effective tax rates (METRs) for a number of physical and intangible assets and for a number of funding sources. The assets include machinery, buildings, inventories, investments in short-lived R&D (that is, investments whose returns last only a few years) and in long-lived R&D (whose returns last many years). Two human capital assets are included -- firm-sponsored training and household-sponsored tertiary education. The calculations incorporate parameters from both the personal and corporate tax codes. They are performed for the “top-bracket” taxpayer and for the “average production worker” and cover between 15 and 22 countries, depending on data availability. The OECD has already used the King-Fullerton method to calculate METRs for physical capital (OECD, 1991) and this paper updates these calculations using established practices. As the method has not yet been applied to household-sponsored human capital, the paper describes the extension to this ...