Since the G20 summit in Rio, the taxation of the wealthiest has seemed omnipresent, without it being easy to make out a clear horizon for any reform. Is this merely an ideological debate, or does a serious effort quietly exist to bring it about? Will it be the object of local political battles, or will it lead to an international consensus? The point here is not to know whether the advent of such a tax is desirable, but whether it can come about. At first glance, the prospect seems barely credible. States’ interests diverge, tax competition remains intense, and the mobility of capital seems to make any coordination illusory. Yet several recent developments call for a more nuanced view of that scepticism.
The United States and Germany block the G20 members’ initiatives
Let us return for a moment to how this theme has been covered in the media in many countries. According to the global inequality report supervised by Nobel laureate in economics Joseph Stiglitz on behalf of the G20, the richest 1% captured 41% of the wealth produced between 2000 and 2024[1]. And since 2020, the planet’s 3,000 billionaires have seen their fortunes grow by 81%[2]. For that reason, at the Rio summit, a tax on the wealthiest, championed by President Lula and backed by France, was debated by the finance ministers present. That meeting resulted in a commitment to cooperate to ensure the taxation of the wealthiest, but no reform was undertaken, notably because of obstruction by the United States and Germany, thereby prompting a wave of reactions in various countries around the world[3]. These discussions therefore led to no concrete progress, while helping to put the question durably on the international agenda.
Deeply divided countries
On this question, the position of the world’s richest countries is fairly disparate. In Europe, Germany, like the United States, is firmly opposed to any such agreement. Its finance minister at the time, Christian Lindner, justified the refusal thus: “We don’t think it’s appropriate. We have an income tax system that is suited to the task”[4]. Argentine President Javier Milei also opposed such a proposal: at the Rio summit in November 2024, he denounced the G20’s tax proposals and refused to support increased state intervention to fight hunger, presenting “free-market capitalism” as the only lasting answer to poverty — without, however, managing to prevent the adoption of the final communiqué by the other members[5]. China, for its part, prefers to compel its billionaires to invest in philanthropic actions rather than to legislate: after Xi Jinping launched the “common prosperity” campaign in 2021, China’s big tech companies pledged more than 100 billion dollars in charitable donations, including 15.5 billion from Alibaba, 15 billion from Tencent and 1.5 billion from Pinduoduo — donations whose voluntary nature is widely doubted[6].
Is the idea of a consensus therefore far-fetched?
Fiscal history shows that major shifts are born not of moral consensus but of political constraint. When financing needs become pressing, states often end up accepting instruments they were still rejecting a few years earlier. One of the examples often cited takes us back to the Second World War, during which President Roosevelt raised the top marginal income-tax rate to 94% on annual income above 200,000 dollars at the time, in order to increase funding for the military effort — a tax on income, not on wealth. Britain and other Allied countries took a similar approach at the time, with a top marginal rate of up to 97.5%. At the end of the conflict, France, in order to rebuild the country, itself launched an exceptional tax on wealth through the “national solidarity levy,” which aimed to tax the capital of the wealthiest at rates of up to 20%. At the time, these measures were not the subject of a consensus but of unilateral decisions by countries. That said, the economy was not as globalised as it is today. So should we anticipate the advent of such a tax in a context where states are so divided on the question?
Some will argue that this consensus is impossible, or even unrealistic, since it would require all G20 members to agree. It is true that the environment is not conducive to such a measure, but some signals suggest otherwise. Three developments deserve particular attention: the multiplication of international initiatives, the gradual shift of the debate in several democracies, and the emergence of growing support even among some holders of very large fortunes. Taken in isolation, each of these elements might seem anecdotal. Together, they perhaps sketch the first outlines of a much deeper shift.
First, over the past decade there have been agreements that were particularly hard to reach and that eventually came about. For example, after many working sessions between 2018 and 2023, the High Seas Treaty was signed by 105 states and entered into force on 17 January 2026[7]. That result was achieved even though many countries were fiercely opposed to it. Another illustration: the tax on multinationals. Under the aegis of the OECD, an agreement was signed by 136 countries in 2021 for a 15% rate applied to multinationals’ profits[8], and the tax has been ratified notably within the European Union, the United Kingdom and Japan.
Second, the atmosphere around the subject is particularly charged. In Hungary, after years of corruption, the new prime minister plans a 1% tax on wealth above 2.5 million euros, in order to correct the inequalities produced by the personal enrichment of several wealthy citizens during the Orbán era[9]. In Mexico, the idea is making its way: at the Barcelona summit in April 2026, President Claudia Sheinbaum committed to assessing a “fair and progressive” tax model, in a country where a third of the population lives in a situation of multidimensional poverty according to CONEVAL[10]. In California, on 3 November 2026, a 5% tax on billionaires’ wealth will be voted on by the electorate following the success of a petition led by the healthcare workers’ union. It could raise more than 100 billion dollars[11] to offset the budget cuts decided by Donald Trump. That prospect is prompting numerous debates and negotiations within the state of California. More broadly, in the United States, Senator Elizabeth Warren introduced a bill in March aimed at taxing wealth above 50 million dollars at 2%, including a 40% exit tax for those who might wish to leave the country. According to Elizabeth Warren herself, this measure would make it possible to collect more than 6,200 billion dollars over the coming decade[12]. If such a law were passed, it would probably drive a broader push to extend it, giving a solid argument to the advocates of this political choice.
Third, at the Davos Forum, nearly 400 millionaires and billionaires signed the “Time to Win” open letter, calling for the wealthiest to be taxed in order to shape a better future[13]. “When even millionaires, like us, recognise that extreme wealth has cost everyone else everything else, there is no doubt that society is dangerously on the edge of the precipice,” they write in their letter[14]. This mobilisation is not an isolated case. In France, several entrepreneurs and large fortunes, such as Jean-Baptiste Rudelle[15] or Elie de Rothschild Jr.[16], have expressed a similar view, supporting the need for a financial effort from the wealthiest, through a Zucman tax, to face today’s challenges.
Factors undeniably in favour of a tax
Beyond ideological debates, far more decisive factors could also accelerate this shift: budgetary needs. States must simultaneously finance demographic ageing, the ecological transition, technological sovereignty, the modernisation of healthcare systems, education and military rearmament. In a context of high debt, the search for new revenue is gradually becoming a necessity rather than a political choice. Even if opposition is widespread and carries its share of arguments, it could be put into perspective by the growing popularity of a tax on large fortunes and by governments’ need to finance the major challenges ahead.
Criticisms nonetheless remain numerous. Opponents point in particular to the difficulty of valuing certain unlisted assets, the risk that the most mobile taxpayers will relocate, the potential effects on investment, and the administrative complexity of such a tax. These objections largely explain why many economists favour other fiscal instruments over an annual wealth tax. However, most of those opposed to this solution do not dispute the diagnosis; they reject the instrument being considered, preferring an overhaul of inheritance law, a tax on realised capital gains, or a tougher fight against tax fraud.
The weak signals of a fiscal shift
History shows that major tax reforms rarely arise from an ideological consensus. They emerge when economic, budgetary or geopolitical constraints make the existing solutions insufficient. Nothing allows us to assert that the international taxation of large fortunes will follow this same trajectory. But the dynamics currently at work share several similarities with those that preceded other major tax reforms. In France, with presidential elections approaching, the debate is likely to be particularly heated. But beyond national divides, the real question lies elsewhere: will states manage to coordinate their interests before their financial constraints force them to? If the needs tied to climate, defence, industrial sovereignty, education and health continue to grow, what looks today like a utopia for some or an aberration for others could become, tomorrow, no longer an ideological debate but simply an instrument of budgetary policy. Such an agreement will probably not see the light of day at the next G20 summit in Miami, since the position of the United States, under Donald Trump’s presidency, should still make a consensus difficult. But the dynamics described here already point to a more cautious conclusion: a global agreement on taxing the ultra-rich looks less improbable today than it did yesterday.
[1]Le Monde — 4 November 2025: https://www.lemonde.fr/economie/article/2025/11/04/un-rapport-du-g20-s-inquiete-du-fosse-des-inegalites-dans-le-monde-et-appelle-a-des-reformes-fortes-en-particulier-fiscales_6651380_3234.html (corrected date: the report was presented on 4 November 2025, not 2024)
[2]Oxfam — Inequality Report 2026: https://www.oxfamfrance.org/rapports/rapport-sur-les-inegalites-2026-resister-au-regne-des-plus-riches/
[3]Les Échos — 19 November 2024: https://www.lesechos.fr/monde/enjeux-internationaux/le-g20-promet-de-mieux-taxer-les-milliardaires-2132426
[4]Climate Home News — 25 April 2024: https://www.climatechangenews.com/2024/04/19/global-billionaires-tax-to-fight-climate-change-and-hunger-rises-up-political-agenda/
[5]France 24 / AFP — 19 November 2024: https://www.france24.com/en/live-news/20241119-taxing-the-richest-what-the-g20-decided
[6] L’Express — 3 September 2021: https://www.lexpress.fr/monde/asie/pousses-par-pekin-des-geants-chinois-de-la-tech-promettent-des-milliards-contre-les-inegalites_2157726.html?cmp_redirect=true
[7]Les Échos — 15 January 2026: https://www.lesechos.fr/monde/enjeux-internationaux/le-traite-sur-la-haute-mer-une-premiere-etape-pour-mieux-proteger-locean-2209933
[8]Le Monde — 8 October 2021: https://www.lemonde.fr/economie/article/2021/10/08/taxation-des-multinationales-un-accord-sur-un-taux-de-15-vient-d-etre-signe-par-136-pays_6097670_3234.html
[9]RFI — 5 June 2026: https://www.rfi.fr/fr/europe/20260605-hongrie-le-gouvernement-de-peter-magyar-doit-trancher-sur-une-taxe-visant-les-grandes-fortunes
[10] AFD, France–Mexico Strategy 2025–2030: https://www.afd.fr/sites/default/files/2026-03/strategie_pays_mexique_2025-2030.pdf
[11]Le Monde — 19 June 2026: https://www.lemonde.fr/international/article/2026/06/19/en-californie-vent-de-panique-autour-d-un-projet-de-taxe-sur-les-milliardaires_6704931_3210.html
[12]CBS — 26 March 2026: https://www.cbsnews.com/news/elizabeth-warren-wealth-tax-plan-ultra-millionaire-tax-act/ — the 6,200 billion-dollar figure is to be attributed explicitly to Elizabeth Warren herself, not to an independent estimate.
[13]Le Figaro — 21 January 2026: https://www.lefigaro.fr/international/forum-de-davos-des-millionnaires-reclament-une-hausse-des-impots-pour-les-ultrariches-20260121
[14]“Time to Win” open letter: https://timetowin.world/
[15] BFM Business — 26 September 2025: https://www.youtube.com/watch?v=gZE5PL9Bp8k&t=28s
[16] Destin de femmes — 27 November 2025: https://www.youtube.com/watch?v=d-Lu2qUmEPw&t=870s&pp=ygUVZWxpZSBkZSByb3Roc2NoaWxkIGpy
