The Economics of the Global Minimum Tax

This paper shows that the OECD inclusive framework of Pillar Two fails to implement the claimed 15% minimum corporate tax for all subsidiaries of multinational corporations that are not shell companies. The reason is that the Substance-based Income Exclusion of Pillar Two allows to tax-deduct payroll costs and user costs of intangible assets twice from the tax base of the top-up tax. Employing a standard multinational firm model, we show that Pillar Two changes the employment, investment and import incentives. For a sufficiently large cost share of labor and/or capital, the Substance-based Income Exclusion is equivalent to a production subsidy