International competition in corporate taxation: evidence from the OECD time series[‘Agglomeration, integration and tax harmonization’]

Despite numerous studies, controversy remains about the impact of economic globalization on corporate taxation. Theoretical models of tax competition generate different predictions about trends in the level of tax burdens and the degree of convergence in tax burdens across countries. In this paper we present a purely empirical analysis of the evolution of tax burdens across OECD countries since the 1950s. Issues of measurement and methodology have contributed to the inconclusive character of studies to date, so we begin with an assessment of alternative measures of the burden. Problems with some commonly used measures of the tax burden are considered and the most plausible measures identified. Descriptive analysis of these time series reveals no evidence of a competitive ‘race to the bottom’ in corporate taxation and little evidence of even a harmonization of the tax burden. Many inferential studies of corporate taxation base their conclusions on cross-sectional analysis; in contrast, we adopt an explicitly time-series method to what are essentially time-series questions. Cointegration methodology originally developed to study issues of convergence of living standards is applied, and fails to reveal evidence of convergence of tax burdens for the OECD and Europe as a whole. It does, however, indicate that there has been some harmonization within smaller groups of countries, mainly in northern Europe. Important questions remain about the effectiveness and impact of corporate taxation in an increasingly open and integrated global economy, but we find little evidence to support fears that the burden of taxation is being lifted from corporations.— Kenneth Stewart and Michael Webb