The faltering legitimacy of international tax law

International taxation has taken a central role in the ongoing political and economic crisis. There is a growing consensus in society that there is a need to change the current rules and norms of international taxation, since the changes in society are not properly reflected in the body of law called 'international tax law'. The starting point of this study is therefore that international tax law is struggling with legitimacy problems in a society that is changing very quickly. The objective of this study is to improve the legitimacy of international tax law. In this respect, it focuses on two separate 'tracks': the legal framework of international tax law and the contribution of social-scientific knowledge to the legitimacy of international tax law. The first part of the study concerns a research of the development of international tax law in the period following the Second World War. This includes an analysis of the changing characteristics of international tax law and the development of the dominant norms of international taxation. The second part of the study considers the possibilities to improve the legitimacy of international tax law. In this respect, the study considers both the work of the German philosopher and sociologist Jürgen Habermas, and the possibilities and limitations of the contribution of social-scientific knowledge to the contribution of the legitimacy of international tax law. The latter element is, for example, relevant in order to evaluate the domination of capital import neutrality and capital export neutrality as ‘sources’ of the legitimacy of international tax law in the history of this field of law. Finally, the third part of the study does recommendations to improve the legitimacy of international tax law on the basis of the findings of the first parts of the study. This includes, amongst others, a different understanding of international tax law that is called ‘deliberative international tax law’.