The research, commissioned by Network of Unions for Tax Justice and the Vienna Chamber of Labour and is the first to model the global impact of unitary taxation; a reform which would see multinationals taxed as single entities with their tax obligations split among states through a formula based on factors such as sales and labour force.  Current rules allow multinationals to use accounting tricks and subsidiaries to artificially shift trillions in profits away from where they are actually generated and into tax havens. 

The study will be presented to negotiators currently meeting at the UN in New York this month to draft a  Global Tax Convention. The findings challenge the narrative that reform would harm major economies, instead showing that countries like the US, Germany, the UK, and Australia stand to gain significantly from ending profit shifting. Tax revenues in high-income countries would grow by almost 70%, reflecting the restoration of taxing rights over real economic activity that is currently booked in tax havens. 

Haley Quinn Acting Deputy Director for Health Issues at the American Federation of Teachers said: "Healthcare workers faithfully pay their taxes while caring for our most vulnerable populations. So why, then, should wealthy private health corporations be afforded tax havens, all while claiming they can’t afford to pay workers more?" 

Tax Havens Lose, Real Economies Win 

Tax havens which currently enable multinationals to artificially shift profits would face dramatic losses. Pure tax havens like Bermuda and the Cayman Islands risk losing 80-90% of their tax base under most scenarios, exposing the fragility of economic models built on paper profits rather than genuine economic activity and production. 

When employment is weighted more heavily in determining where profits should be taxed, labour-intensive economies gain a fairer share. India's tax base more than doubles, while Indonesia and Brazil see increases of over 40% each — recognition of their substantial but previously under-valued role in global value chains. This restored fiscal space could fund infrastructure investment, new essential workers such as doctors and teachers and expanded social protections — benefits flowing directly back to workers and communities. 

For the vast majority of companies, including small businesses and domestic competitors, the reforms would change nothing while levelling the playing field. Average tax increases for the biggest global multinationals would be around 8%, with the largest jumps concentrated among corporations currently engaged in aggressive profit shifting through tax havens. 

Potential models and designs 

The study examined multiple tax apportionment formulas, finding that balanced approaches like the "double sales" model — which weights both destination sales and employment — offer practical compromises between different economic interests. While some lower-income countries see more mixed results depending on formula choice, this first-of-its-kind research demonstrates how finding the right global balance will require more analysis and collaboration to build a fair profit apportionment model across countries and sectors. 

Contrary to the myth that cutting corporate taxes creates jobs, recent research shows countries with stronger corporate tax systems achieve better employment outcomes and fairer wage distribution. Meanwhile firms engaging most aggressively in tax avoidance rarely reinvest savings in jobs or productive capacity. 

Jayati Ghosh, co-chair of the Independent Commission for the Reform of International Corporate Taxation (ICRICT) said: Multinationals should be taxed in a way that recognises the economic reality that these are single global entities, not a collection of separate units strung together in ways that reduce their tax footprint. Governments must now take action to collect the hundreds of billions of unpaid taxes left on the table in the current system and come up with a fair formula to ensure that companies pay what they owe, where they do business.  

Daniel Bertossa, General Secretary of Public Services International said: "Workers pay taxes on their wages where they work - so why should corporations be allowed to dodge taxes where they make their profits. These urgent reforms would chase hidden profits out of offshore havens, into public coffers and onto corporate balance sheets to be invested in better jobs and wages for workers. 

José Antonio Ocampo, ICRICT commissioner and Professor at Columbia University said:  For the first time, we have empirical evidence that shows what many economists have long suspected: getting rid of the broken transfer pricing system would immediately undercut tax havens.A new global tax system must be designed so that countries can tax profits where value is created, which includes where their workers are located. Only when the global tax rules recognise the labour and resources utilised in the South, will our countries get their fair share of tax revenue to support development and public services