Execu�ve summary Over the last 10 years, governments have launched major ini�a�ves to reduce interna�onal tax

This work leverages the availability of new data on the acvies of mulnaonal companies (such as country-by-country reports) and the offshore wealth of households (from the automac exchange of bank informaon) created by the policy iniaves of the last decade. [...] Previously, policymakers atempted to regulate the definion of the tax base, to address inconsistencies in the definion of profits across countries, to improve the allocaon of profits internaonally – but there was no agreement about tax rates, the key aspect of tax policy. [...] Figure 3: The weakening of the global minimum tax This figure reports the esmated revenue (for the year 2023) of a 20% minimum tax on the profits of mulnaonal companies with no exempons, and the effects of various provisions incorporated in the Pillar Two minimum tax of the OECD Two-Pillar framework: (i) rate of 15% instead of 20%; (ii) carve-out for economic substance (allowing firms to exclude 8. [...] A 20% minimum tax without loopholes would generate the equivalent of 16.7% of global corporate tax revenues; aer the reducon of the rate to 15%, and the carve-out, US, and tax credit loopholes, revenues are reduced to about 4.8%, i.e., cut by a factor of three. [...] Even so, the revenue potenal is large, due to the concentraon of wealth at the top of the distribuon and the low current tax rates of billionaires (Table 2).