Research Theme

International Tax

Low-income countries are more dependent on corporate income tax revenue than richer countries, and at the same time, disproportionately affected by multinational tax avoidance. Our research on this theme investigates ways in which developing countries can protect their tax bases, including through simplified transfer pricing methods and improved tax treaty policies. It also examines the challenges and opportunities developing countries face from their participation in international tax negotiations.

ICTD has also been closely following the developments around the UN Tax Convention. Check out our latest research and analysis here.

Led By

Martin Hearson

Key Resources

Working Paper

Global Rules, Local Realities: Lessons from the Global South on International Tax Standards

June 2026

Martin Hearson, Frederik Heitmüller, Florian Dierich

Working Paper

Scenarios for Negotiating a UN Framework Convention on International Tax

January 2025

Frederik Heitmüller

Partner Publication

A Fairer Global Tax Architecture

September 2024

Martin Hearson, Frederik Heitmüller, Mbakiso Magwape, Suranjali Tandon

Journal Article

Relieving Double Taxation on Cross-Border Services: A Comparative Analysis of Major Exporting Countries

July 2026

Frederik Heitmüller, Aisha Aize Isa, Florian Dierich, Yvette Nakibuule Wakabi

International Tax Library

Working Paper

Developing Country Revenue Mobilisation: A Proposal to Modify the ‘Transactional Net Margin’ Transfer Pricing Method

January 2016

Michael Durst

Working Paper

Measuring Misalignment: the Location of US Multinationals’ Economic Activity Versus the Location of their Profits

November 2015

Alex Cobham, Petr Janský

Working Paper

A Price-Based Royalty Tax?

October 2015

Kimberly A. Clausing, Michael Durst

Working Paper

Limitations of the BEPS Reforms: Looking Beyond Corporate Taxation for Revenue Gains

September 2015

Michael Durst

Research in Brief

Is the International Tax System Fit for Purpose, Especially for Developing Countries?

September 2015

Sol Picciotto

Unitary Taxation in Federal and Regional Integrated Markets

September 2015

Erika Dayle Siu

Lessons for International Tax Reform from the US State Experience under Formulary Apportionment

September 2015

Kimberly A. Clausing

Working Paper

Limitations on Interest Deductions: A Suggested Perspective for Developing Countries

September 2015

Michael Durst

Working Paper

Unitary Taxation in the Extractive Industry Sector

September 2015

Erika Dayle Siu, Sol Picciotto, Jack Mintz, Akilagpa Sawyerr

Working Paper

Unitary Taxation: Tax Base and the Role of Accounting

September 2015

Prem Sikka, Richard Murphy

Working Paper

The Tax Policy Outlook for Developing Countries: Reflections on International Formulary Apportionment

September 2015

Michael Durst

Working Paper

Global Taxes and International Taxation: Mirage and Reality

September 2015

Richard M. Bird

10 August 2026

The UN Tax Convention draft protocol on cross-border services: clear direction but crucial details left open

Frederik Heitmüller

The much awaited Co-Lead’s draft protocol on the taxation of income from cross-border services was published on 20 July 2026….

4 August 2026

Double taxation relief on remote services – implications for UN Tax Convention Protocol 1 negotiations

Frederik Heitmüller, Aisha Aize Isa, Florian Dierich, Yvette Nakibuule Wakabi

To inform ongoing negotiations on the taxation of cross-border services at the UN, we wrote a study on double tax…

26 November 2025

A new era or business as usual? Why the UN Expert Committee on Tax is still relevant

Florian Dierich

The Committee’s most prominent contribution is the UN Model Tax Convention, which provides model language for the negotiation of bilateral…

4 November 2025

UN Tax Convention Reading List Part 3: Protocol 2 – Dispute Resolution and Prevention

Florian Dierich, Frederik Heitmüller

In Part 3 of our UN Tax Convention reading list, we bring together key research and analysis on dispute prevention…

31 October 2025

UN Tax Convention Negotiations: Where are we at and where are we headed?

Frederik Heitmüller, Florian Dierich

In preparation for the Nairobi session, two documents were shared for discussion: a Framework Convention Template prepared by the Co-lead…

8 October 2025

UN Tax Convention reading list part 2: Protocol 1 – Taxation of cross-border services

Florian Dierich, Frederik Heitmüller

The negotiations for Protocol 1 present a genuine opportunity to revisit how cross-border services are taxed. But, as we explored…

21 September 2026

Call for Papers: Research workshop on the UN Framework Convention on International Tax

Frederik Heitmüller, Martin Hearson

With only one year to go, the negotiations on the UN Framework Convention on International Tax Cooperation and its…

27 July 2026

ICTD launches report on 15 years of research and the future of development finance

The International Centre for Tax and Development (ICTD) has officially released its major report, Taxing Smarter: Advancing Reform Through Research…

29 June 2026

New ICTD research shows uneven adoption of international tax standards by lower-income countries

Martin Hearson, Frederik Heitmüller

This paper by Martin Hearson, Frederich Heitmüller and Florian Dierich, draws together findings across all seven country case studies, identifying…

20 March 2026

Tax treaties in spotlight as UN Tax Convention negotiations deepen

Martin Hearson, Frederik Heitmüller, Florian Dierich

When member-states convene in New York this August for the fifth substantive session on the UN Framework Convention on International…

30 January 2025

UN Tax Talks: New research highlights key scenarios at next week’s historic negotiations

Martin Hearson, Frederik Heitmüller

New research from the International Centre for Tax and Development (ICTD) provides crucial insights into the challenges and opportunities shaping…

19 November 2024

G20 Brazil: How does taxation fit into the agenda?

Fabrizio Santoro, Vanessa van den Boogaard, Martin Hearson, Max Gallien, Frederik Heitmüller

Researchers from the International Centre for Tax and Development (ICTD) participated in crafting such recommendations in a number of policy…

Academic Symposium on the UN Framework Convention on International Tax Cooperation

Virtual

6 February 2026 – 15:30

•

Timezone: Europe/London

ICTD Research Director Martin Hearson and Associate Postdoctoral Fellow Frederik Heitmüller will be speaking at the Academic Symposium on the UN Framework Convention on International Tax Cooperation, hosted by the International Tax Program at the NYU School of Law.

Lecture: The need for more inclusive, equitable tax and multilateral systems

Virtual

3 December 2025 – 16:00

•

Timezone: Europe/London

Fresh from the UN Tax Convention negotiations in Nairobi earlier this month, Mukumba will discuss why reforming the global tax architecture matters for everyone, not just the global South that is pushing for change.

Conference: Digital Service Taxes: A fair and effective way to tax the data economy?

In person

25 September 2025 – 13:30

•

Timezone: Europe/London

Allard Pierson Museum, Oude Turfmarkt, Amsterdam, Netherlands

ICTD Research Officer Florian Dierich will be presenting the Centre’s research in a panel exploring policy options around an “improved DST” compared to other alternatives.

WEBINAR: Next Steps for the UN Convention on Tax: Mapping Priorities

Virtual

16 July 2025 – 14:00

•

Timezone: Europe/London

Countries around the world are losing billions to illicit financial flows, tax avoidance, tax evasion, and unfair allocation of taxing rights—reflecting a global tax framework which is no longer fit for purpose. The UN Framework Convention on International Tax Cooperation