Tax Treaty Interpretation in light of the Vienna Convention on the Law of Treaties

Academic Chairman of IBFD. Full Professor of Tax Law at the University of Salerno and Holder of a Jean Monnet ad Personam Chair in European Tax Law and Policy at WU Vienna.

Honorary Professor at the Ural State Law University (Russia) and at the University of Cape Town (South Africa). Honorary Doctor at the University of Örebro (Sweden). Visiting Professor (2022/2023) at the NYU School of Law.

Chief editor of the journals World Tax Journal and of ITAXS, the IBFD Doctoral Series and the Series of International Tax Law by Bloomsbury and of the IBFD Global Tax Treaty Commentaries. Co-editor of the journal Diritto e Pratica Tributaria Internazionale. Editor and author of numerous books, articles and book chapters, published and/or translated in 12 languages, on international and European tax law, which are his core research areas.

Secretary General of the European Association of Tax Law Professors. Co-Chair of the Tax Committee of the International Law Association. Member of the Permanent Scientific Committee of the International Fiscal Association.

Dr. Katerina Perrou is a Lawyer, and Post-doctoral Fellow and Assistant Lecturer in Tax Law at the Law School of the National and Kapodistrian University of Athens. She has studies in Athens (bachelor’s degree and LLM in Public Law) and in London, where she completed her PhD on “Taxpayer Participation in Tax Treaty Dispute Resolution” at the Institute of Advanced Legal Studies, University of London, UK. 

In 2016-2018 she joined the IBFD, Amsterdam, the Netherlands, as postdoctoral research fellow on Tax Treaty Issues.

She is the Secretary General of the Greek IFA Branch.

Currently, she serves as Legal Counsel to the Governor of the Greek Independent Authority for Public Revenue.

Prof. Dr. Stef van Weeghel is Global Tax Policy leader at PwC, professor of international tax law at the University of Amsterdam and chair of the Board of Trustees at IBFD. Before he joined PwC in 2009 he was partner at law firms Stibbe and Linklaters, where he practiced in Amsterdam and New York.  
His focus is on tax policy and tax controversy, with research covering tax treaties and investment treaties. He regularly acts as expert-witness or co-counsel in tax disputes and in investment treaty and commercial arbitration. He is consulted by the private sector and governments, chaired a government-appointed Dutch tax reform committee, appeared before both chambers of the Dutch Parliament and the TAXE and PANA Committees of the European Parliament. He is immediate past chair of the PSC of IFA, an honorary member, has acted as IFA branch and general reporter, as chair of the IFA-OECD Seminar, and as secretary and chair of the Dutch branch of IFA. He authored and co-authored several books and numerous articles on Dutch and international taxation and has lectured extensively. He received his law degree from the University of Leiden (1983), was admitted to the Amsterdam Bar (1987), obtained an LL.M. in Taxation from NYU (1990) and received a doctorate in law from the University of Amsterdam (1997).

Alexander Rust is Professor of International Tax Law at Wirtschaftsuniversität Wien and Director of the Master Program Digitalization and Tax Law. Before joining the Institute of Austrian and International Tax Law Alexander Rust held positions as Acting Assistant Professor in the International Tax Program at New York University and as Professor of Tax Law and Director of the Master Program in European and International Tax Law at the University of Luxembourg. He specializes in all areas of tax law but is also fascinated by constitutional and European law. He is a frequent guest lecturer at universities in and outside Europe.

Daniel Gutmann is professor of domestic, international and european tax law at the Sorbonne Law School (University Paris-1) where he is the Director of a research centre in taxation (Sorbonne-Fiscalité-Finances Publiques). He wrote numerous articles in tax matters and is the author of a book on taxation of businesses (Droit fiscal des affaires, Lextenso, 13th ed., 2022) which was awarded the Legal Book Special Prize by the French Constitutional Court and the “Club des Juristes”. He has also published a book on the methodology of tax law interpretation (Sources et ressources de l’interprétation juridique. Etude de droit fiscal, Lextenso, 2023).

He is also a partner at CMS Francis Lefebvre Avocats, in charge of the Tax Intelligence Department. Within CMS, Daniel is the Head of the CMS Treaty and EU Tax Law Group and a member of the steering committee, CMS Global Tax.

Beyond his activities at University and CMS, Daniel is the Scientific Director of “Fiscalité internationale”, a French tax review dedicated to international tax law.

He is the Chairman of the Academic Committee of the European Association of Tax Law Professors (EATLP), a member of the Permanent Scientific Committee of IFA and of the Scientific Committee of the French IFA Branch.

Until 2020, he was a member of the “Conseil des prélèvements obligatoires” (the French Tax and Social Charges Board).

Craig is a Professor of Taxation and Law at the University of Auckland, Faculty of Law. Before taking a chair he was for 14 years a tax partner at KPMG and for eight years subsequently a tax partner at Chapman Tripp. His research areas are particularly in tax avoidance, international tax and corporate tax. He is the Director of the University of Auckland’s Master of Taxation Studies programme and he has written extensively on tax issues. Craig is a member of the Tax Advisory Group of Chartered Accountants in Australia and New Zealand, the tax committee of CPA Australia, and was a member of the Permanent Scientific Committee of the International Fiscal Association and the New Zealand Government’s Tax Working Group (2018-2019). He is the author of a number of journal articles in publications such as the British Tax Review, Canadian Tax Journal, Australian Tax Forum, World Tax Journal, and the New Zealand Universities Law Journal and has authored the JF Northey prize winning book International and Cross-Border Taxation in New Zealand published by Thomson Reuters (2015 and 2018), and Taxing the Digital Economy: Theory, Policy and Practice, Cambridge University Press (2021). 

BCom, LLB (Hons), LLM (Camb), PhD (Camb), FCA

Sjoerd Douma is Professor of International & EU Procedural Tax Law at the University of Amsterdam and Partner at Lubbers, Boer & Douma in The Hague. Prior to his appointment in October 2017, he was a professor at Leiden University. Sjoerd is a member of the Permanent Scientific Committee of the International Fiscal Association. He has specialized in corporate income taxation, tax treaties, European tax law and procedural law. Sjoerd has been a Deputy Judge in the Court of Appeals of Arnhem-Leeuwarden, a Deputy Judge in the District Court of Haarlem and Visiting Professor at Université Panthéon-Assas (Paris, France). He is a permanent contributor to leading Dutch and international tax journals. He has authored and co-authored numerous publications and reports on national, international and European tax law. Prior to joining Lubbers, Boer & Douma in March 2017, Sjoerd has practiced tax law at one of the ‘big four’ tax advisory firms. Sjoerd has represented taxpayers before the tax authorities, the Dutch tax courts (including the Dutch Supreme Court), the European Commission and the Court of Justice of the European Union.

Scott Wilkie is a Research Fellow of the Amsterdam Centre for Transfer Pricing and Income Allocation, part of the Amsterdam Center for Tax Law of the University of Amsterdam, a recently retired Distinguished Professor of Practice at Osgoode Hall Law School, York University, and a retired partner of and senior counsel to Blake, Cassels & Graydon LLP. Widely published, he speaks and writes broadly about taxation, notably international taxation and tax policy. He is a former vice-chair of the Permanent Scientific Committee of the International Fiscal Association, served as president of the Canadian branch of the International Fiscal Association, and is a past chair of the Canadian Tax Foundation.

Prof. Dr. Dr. h.c. Michael Lang is Vice Rector Research and Human Resources of WU, Head of the Institute for Austrian and International Tax Law of WU (Vienna University of Economics and Business) and Academic Director of both the LL.M. Program in International Tax Law and of the doctoral program in international business taxation (DIBT) of this university. He is President of the Austrian Branch of the International Fiscal Association  (IFA).

John Avery Jones is a retired Judge of the UK Upper Tribunal (Tax and Chancery Chamber).

Jean-Blaise Eckert, Secretary General of IFA, is a partner at Lenz & Staehelin and co-head of the tax group. His practice areas include tax, private clients, contract law and commercial.

He speaks French, English and German. Jean-Blaise studied law at the University of Neuchâtel and was admitted to the Bar of Neuchâtel in 1989 and to the Bar of Geneva in 1991. He studied business administration at Berkeley, Haas Business School, where he acquired an MBA in 1991. He received his diploma as a Certified Tax Expert in 1994 and is a Certified Specialist in Inheritance Law.

Jean-Blaise is considered as a leading lawyer in Switzerland. He advises a number of multinational groups of companies as well as HNWIs. He sits on the board of a number of public and private companies. Jean-Blaise is a frequent speaker at professional conferences on tax matters. Jean-Blaise is Secretary General of the International Fiscal Association (IFA).

Bruno Gibert joined CMS Francis Lefebvre Avocats as an equity partner in 2001. He specializes in international taxation with a particular focus on transfer pricing matters. On this last domain, he heads the transfer pricing group the CMS network has put in place within the tax practice. He has 16 years' experience in the government service, where he was in charge of international tax affairs (negotiation of tax treaties with foreign countries, OECD and EU work, and competent authority). He used to be co-chairman of the OECD forum on harmful tax practices (1996-2001). He was also Chairman of the EU joint forum on transfer pricing from 2002 to 2019. He has been appointed as an independent person of standing for the EU Arbitration Convention and the EU Directive on Dispute Resolution. Former chair of the International Fiscal Association (IFA) French branch, he is also a member of the board of trustees of the International Bureau of Fiscal Documentation (IBFD). Author or co-author of several books on international tax matters, he regularly publishes articles on these matters in French and international publications.

Johann Hattingh is Professor in the Department of Commercial Law at the University of Cape Town, South Africa. His PhD thesis, awarded by the University of Cambridge, formulated an integrative theory for tax treaty interpretation. He holds two LLM degrees, one from the University of Cape Town and the other from Leiden University in the Netherlands. He obtained B.Com (Law) and LL.B degrees from Stellenbosch University. Since 2003 he holds an association with the International Bureau of Fiscal Documentation (IBFD) in Amsterdam, where in 2019 he took up the Chief Editorship of the Bulletin for International Taxation. 

Professor Hattingh has given lectures and seminars at the International Tax Centre of Leiden University, Stellenbosch University, the University of Cambridge, the Institute for European and Comparative Law at the University of Oxford and the Institute of Austrian and International Tax Law at Vienna University of Business and Economics. At the University of Cape Town, he convenes Africa’s only master’s degree programme fully devoted to interdisciplinary study of international taxation. He has acted as senior international consultant for the UN Economic Commission for Africa, the International Monetary Fund, and participated in the tax work of NEPAD on behalf of the African Union. He is regularly consulted by public and private sector organisations across Africa.  His professional memberships include the International Tax Group, the International Tax Law Committee of the International Law Association and the permanent scientific committee of the International Fiscal Association.

Chloe Burnett SC is a tax barrister based in Sydney, Australia.  She has appeared in a number of significant international and corporate tax cases.  She is the Vice-President of the Australian Branch of IFA.  In the period 2018 to 2020 she was the Chair of the Recent Developments Panel at the IFA Congress.  Chloe studied law, finance and accounting as an undergraduate at Sydney University and she has a LLM from New York University.  Chloe lectures in Interpretation of Statutes, Contracts and Treaties in the LLM program at The Sydney Law School, and regularly publishes articles on international and corporate tax and on legal interpretation.  Before becoming a barrister, Chloe was a solicitor at Allens and worked as an Associate to the Honourable Justice Edmonds of the Federal Court.  She has also worked for Macquarie Bank in Sydney and Slaughter and May in London.

The Hon Jennifer Davies S.C. is a retired judge of the Federal Court of Australia and during her time on the bench was the national co-ordinating judge of the Taxation National Practice Area. Prior to her appointment to the Federal Court she was a judge of the Supreme Court of Victoria, sitting in the Commercial Court division and before then, a member of the Bar from May 1983. She took silk in 2004.

She is an Honorary Principal Fellow at the University of Melbourne lecturing in postgraduate courses and on the Melbourne University Tax Advisory board. She is also on the board of the International Association of Tax Judges and is a member of the Australian Academy of Law, the International Academy of Estate and Trust Law and the International Fiscal Association, and a Fellow of the Taxation Institute of Australia.