On Thursday 1 December 2016 at 13.45 hrs, Francisco Sepulveda Ramirez will defend his doctoral thesis ‘Residence in Tax Treaties' at the Academy Building of Leiden University. Supervisor is Professor F.A. Engelen.

How do tax treaties have to be explained and implemented, and what role does the supranational regulatory process play in this? Which objectives are meant to be used in establishing tax regulations and to what extent are such legislative practices undertaken in a goal-oriented manner?.

In the past few years, an increasing number of multinationals have made the news for large-scale use of tax planning opportunities. The Organisation for Economic Collaboration and Development (OECD) and the European Commission are studying these cases closely and investigating whether the current concepts…

Minister Silvania of Curaçao has announced that Germaine Rekwest, who was awarded a PhD from Leiden University in September, will support him on treaty policy for Curaçao. The minister announced this in his travel report.

Tax scandals, like the Panama Papers, the Paradise Papers, and the Pandora Papers, have made taxation a major topic of public debate. Learn more about this in the new minor Tax and Society: Building a Sustainable and Fair Tax System.

The study of tax law covers the tax system in its full width. It includes domestic, international and European tax law.

In this PhD-thesis several new and existing data science application are described that are particularly focused on applications for tax administrations.

Loopholes in international tax legislation contribute to the misuse of tax rules by multinationals. Leiden University legal experts investigate how the complex national and international tax rules can be made more consistent in order to create a better tax system.

On Thursday 16 November, Dirk Broekhuijsen defended his doctoral thesis entitled ‘A multilateral tax treaty: designing an instrument to modernise international tax law’. The supervisors are Professor F.A. Engelen and Professor S.C.W. Douma.

Multinationals use loopholes in the tax treaties between different states. A possible solution would be to eliminate all these loopholes in one go by creating a central global treaty. Leiden researchers are investigating whether this kind of mega-treaty is feasible.

The master’s programme 'Fiscaal Recht' provides you with in-depth theoretical and practical knowledge on all the ins and outs of tax law.

The EUTAXGOV Chair will address the EU Standard of Tax Good Governance. This Standard has been introduced in 2008 by the ECOFIN Council with a view to tackle tax fraud and evasion by companies and individuals and as a pre-condition for third (non-EU) countries that receive EU development aid, and concluded…

Do you like solving complex legal puzzles? Do you like analysing problems? If so, the bachelor’s programme Fiscaal Recht is right for you.

Courses EU Tax Governance (EUTAXGOV).

The Institute of Tax Law and Economics at Leiden Law School has three departments: the Department of Tax Law, the Department of Economics and the Department of Business Studies. The Institute brings together research and teaching at the point at which, on the one hand, law and, on the other, fiscal…

In this paper, Kantorowicz aims to track the persistent effect of former partitioning borders on property tax rates in Poland.

On 10 October 2018, Richard Resch defended his doctoral thesis 'The Interpretation of Plurilingual Tax Treaties'. The doctoral research was supervised by Prof. mr. C. van Raad.

On 13 January 2022, Pie Habimana defended the thesis 'Harmful Tax Competition in the East African Community'. The doctoral research was supervised by Prof. H. Vording and Prof. S.C.W. Douma (UvA).

Complex systems can be characterized as systems in which multiple components interact with each other, often in non-linear ways. The main goal of this research will be to investigate if and how the international tax system can be defined and modelled as a complex system. Approaching the international…

Tax scandals, like the Panama Papers, the Paradise Papers, and the Pandora Papers, have made tax avoidance by large multinationals and rich individuals a major topic of public debate. Policymakers are pushed to close tax loopholes and reform the global tax system. But this is no easy task.

Ideology and Actions

Assessing the feasibility and legitimacy of the current model of global tax governance and the role of the OECD and EU in international tax law-making.

Dutch newspaper Trouw investigated the tax position of multinational Cargill. Their conclusion? Cargill appears not to pay taxes over their profits. Trouw asked Jan van de Streek, Professor of Tax Law, and PhD candidate Josephine van der Have for an explanation. Prior to this, Van der Have had also…

On Thursday 1 December 2016 at 13.45 hrs, Francisco Sepulveda Ramirez will defend his doctoral thesis ‘Residence in Tax Treaties' at the Academy Building of Leiden University. Supervisor is Professor F.A. Engelen.

Sarah Giest, Assistant Professor at Leiden University, and Ishani Mukherjee researched the topic of 'Behavioural Insights Teams (BITs) and Policy Change: An Exploration of Impact, Location, and Temporality of Policy Advice'.

One of the EU's most heralded weapons against tax avoidance and evasion falls prey to political whims, is applied arbitrarily, and lacks transparency, according to tax observers and lawmakers.

PhD defence

No, the Netherlands is not a tax haven, the new State Secretary for Tax Affairs Marnix van Rij said shortly after his introductory meeting with Dutch Prime Minister Rutte. Yet there are numerous reports that describe the Netherlands' role as a tax haven.

On Friday 17 November 2017, H.E. Dr. María Fernanda Espinosa, Minister of Foreign Affairs and Human Mobility of the Republic of Ecuador gave a lecture on Fairness in Global Taxation at the Grotius Centre for International Legal Studies at Leiden University, Campus The Hague.

The Netherlands remains one of the most important locations when it comes to tax evasion. According to Tax Justice Network only the British Virgin Islands, the Cayman Islands and Bermuda play a greater role.

Under #TheCode European media report about Martijn Nouwens’s research on the secretive EU Code of Conduct Group which is tasked with tackling harmful tax competition in Europe. The stories expose to the wider public for the first time how this diplomatic high-level working group of EU Member States…

The benefits department of the Dutch Tax Administration has attempted to reach backroom agreements with the judiciary about the decision period in benefits cases. Lecturer in tax law Martijn Nouwen says this harms the legal protection of victims.

In her teaching and research, Mosquera primarily seeks the connection between tax law and other disciplines. Her appointment is effective as of 1 November 2021.

This book offers a concise and accessible introduction to debates about expertise, policy-making and democracy. It uniquely combines an overview of recent research on the policy role of experts with discussions in political philosophy and the philosophy of expertise.

What does it mean to do public policy ethics today? How should philosophers engage with ethical issues in policy-making when policy decisions are circumscribed by political and pragmatic concerns? How do ethical issues in public policy differ between areas such as foreign policy, criminal justice, or…

In this article Fisher, Klein & Codjo introduce the FOCUSdate Project and they show how the sentiment data provide unique abilities to analyze Russia's and Iran's reactions to US policies and events and NGO human rights campaigns.

More than 130 countries, including the Netherlands, have decided to introduce a minimum corporate tax rate of 15 percent. The plan would lead to 125 billion euro in extra tax revenue globally.

Before he became Minister of Finance, CDA leader Wopke Hoekstra invested for years in a shell company in the Virgin Islands. This has been revealed in leaked documents known as the Pandora Papers. How exactly does tax avoidance work? And are there other options? Tax lawyers Jan Vleggeert and Tanja…

Researchers from the Department of Tax Law were lead authors of a report on corporate taxation and digitalization for the World Economic Forum.

Jan Vleggeert is a tax specialist with an independent and critical voice in the debate on tax avoidance by multinationals. His appointment commenced on 1 October 2019.

In 2017, at the start of the Rutte III cabinet, tax scholars Leo Stevens and Koen Caminada presented a blueprint for a new tax system. Today, four years on, they observe that the cabinet has put little effort into innovations in the area of tax.

How do crises produce changes in specific European Union foreign policy areas, and how should we conceptualise these policy changes?

In September 2021 the CWTS open science policy came into effect. This policy deals with open access publishing, open research data, and open source software. All research projects carried out at CWTS are subject to the CWTS open science policy.