About me

As the fifth of seven children in a family from Rotterdam, I started my professional career at the Royal Conservatoire in The Hague. While still at secondary school (the Erasmiaans Gymnasium), I studied (classical) piano as a main subject with Marcel Baudet and Rian de Waal at the school for young talent from 1992 to 1995. In 1998, I decided to study law at the Erasmus University Rotterdam (EUR), obtaining degrees in Dutch Law and Tax Law (cum laude) in 2004. My master thesis "Compartmentalization under tax treaties" was awarded the NOB/LOF thesis prize in 2004.

Immediately after my graduation, I started my doctoral research in the field of European tax law as a PhD-candidate for three days a week, first at the EUR and then from 2007 at the Fiscal Institute Tilburg at Tilburg University. In 2011, I defended my PhD thesis entitled "Freedom of investment  between EU and non-EU member states and its impact on corporate income tax systems within the European Union" at the economics faculty of Tilburg University. My thesis was awarded the European Doctoral Tax Thesis Award in 2012. During the same period, in addition to my teaching and management duties, I was responsible for setting up the English-language master's programme International Business Taxation and getting it accredited, as a programme director. This master's programme has been offered at Tilburg University since 2013.

As of April 1, 2016, I was professor of Corporate Taxation and Corporate Finance by special appointment at Tilburg University, for three days a week for a period of five years. From my inaugural address it follows that my research focuses, among other things, on the European approach to tax avoidance by multinational corporations.I argue for a reconsideration of the existing international income allocation rules for the taxation of multinational companies, on the basis of economic reality rather than on the basis of legal form. In doing so, I build on my recommendations made in 2011 as part of my doctoral research. The increasing digitisation of the economy and the growing tension this creates with the existing tax system, has further increased the need for a rethink. Consequently, as part of my special chair in Tilburg, I have been explicitly and increasingly concerned with the taxation of digital enterprises. In this context, I was appointed as a visiting professor at the Université Paris I: Panthéon-Sorbonne in the academic year 2018-2019. In this role, I focused on the impact of the digitising economy on the taxation of internationally operating companies and individuals.

As of September 1, 2021, I have been appointed as a professor by special appointment of Taxation Digital Economy for two days per week at the University of Amsterdam for a period of five years. The special chair was established on behalf of theFoundation for the Promotion of Education and Research at the Faculty of Law and - like my previous special chair in Tilburg - is fully funded by EY. I currently work at the Amsterdam Centre for Tax Law (ACTL) and am also one of the academic leaders of the UvA Research Project - Designing the tax system for a cashless, platform-based and technology -driven society (CPT). In addition to my teaching duties, I conduct interdisciplinary research on the taxation of the digitised economy, and in particular on the tax challenges and opportunities with respect to online platforms. Building on my previous research, I am looking to answer the question of whether, and if so, how the international tax system should be adapted in light of the digitising economy. In doing so, the goal is for taxpayers to pay their fair share in the right place.

I have more than 150 academic and non-academic publications to my name, and regularly speak at (inter)national conferences and seminars, and give (guest) lectures.

In addition to my academic work, I have been employed by the international consulting firm EY since 2002 on a fixed salary (below the so-called Balkenende-norm) and on a full-time basis. Under the agreement which I have with EY, I spend three days a week working for EY in Amsterdam (until September 1, 2021: two days), and have the remaining two days for my academic work. Within EY, I have an independent, non-commercial role in the areas of internal information provision and tax technical support and development since 2002. Since October 1, 2020, I am the head of EY's tax knowledge center. EY has always acknowledged and fully supported my academic ambitions. It goes without saying that EY has no control over my academic research.

On a personal note, I have lived in Amsterdam with my wife and 2 sons since 2014. I enjoy spending my free time with my family. Furthermore, I am an avid marathon runner (for example in 2006 in Rotterdam (3:13) and in 2021 in Amsterdam (3:33)). FFurthermore, I still like to play the piano, partly because I am convinced that music and science can reinforce each other extremely well. 

About my research

My research is normative-legal. I describe certain social problems from the point of view of the prevailing tax law, and then use a transparent normative assessment benchmark to evaluate whether, and if so, to what extent, the prevailing law requires adjustment. To date, the benchmark of the "genuine economic link" in combination with the idea of "source country entitlement" has always been leading in my research. This means that income should be taxed where it is actually generated, and not where it is ultimately received. In this way, taxation should have as little positive or negative impact as possible on the behaviour and choices of economic agents (e.g., companies, employees and self-employed workers) operating internationally. This contributes to fair competition in the market. At the moment, the big challenge in an internationally mobile and digitising economy is how to determine the said "link" with a country. With my research, I want to contribute to an answer to this complex issue, in the coming years. 

At the same time, tax rules should be knowable and predictable. For this reason, I for example take a critical view on the European Commission's approach to tackling international tax avoidance through European competition law. Tackling international tax avoidance is a task for the national or European legislator.

My research so far is not empirical. Questions such as: "Would it be good for the Dutch business climate to abolish the dividend tax?", thus fall outside my research area. Incidentally, based on the benchmark of the "genuine economic link" and "source country entitlement", I have been arguing for years for strengthening the dividend tax in corporate relationships. At the same time, on the basis of the applicable European law (in 2018), I have pointed out the vulnerability of this tax in European law outside of corporate relationships.

About the funding of my chair

My special chair is funded by EY. As noted above, I am seconded by EY to the ACTL for two days a week (EY does not charge the UvA for this). In addition, EY makes an annual sum of 25,000 euros available to the ACTL. It has been agreed that this sum may only be used professionally for the benefit of my research, i.e., not for me personally. The funds can for example be used for the hiring of one or more additional researchers. Under the aforementioned agreement, EY has no say in how these funds are used. With this funding, EY is once again enabling me (and other young researchers) to further develop academically. EY has never influenced what I publish in my academic capacity, either during my appointment as a professor in Tilburg or during my appointment in Amsterdam. Nor have I ever submitted an academic publication to EY for approval. A concrete example of this is my PhD thesis that appeared in 2011, when the public debate on tax avoidance by multinational companies was still in its infancy. In my thesis, I make a concrete proposal for a European directive for, among other things, tackling letterbox companies in international structures in order to counter tax avoidance by multinational companies, by introducing mandatory withholding taxes, such as a dividend tax (from page 828).