A 3% tax on cienmillonarios could generate sufficient revenue to fund a significant portion of global humanitarian aid and prevent up to 29.5 million deaths by 2030, according to a scientific study published in the journal The Lancet and led by the Barcelona-based ISGlobal institute.
A 3% Levy on Cienmillonarios
The research analyzes data on mortality and development assistance across 59 low- and lower-middle-income countries between 2002 and 2021. According to the findings, higher levels of Official Development Assistance are associated with a reduction in general mortality of up to 24% and a drop of up to 33% in deaths among children under five years old.
Donor Retrenchment and Military Shifts
Despite these demonstrated health impacts, donor nations are scaling back their foreign aid commitments. Major donor governments, including Germany and the United Kingdom, have announced reductions in their international assistance budgets. Most notably, the United States has signaled an 83% cut to its foreign aid allocations—a reduction that an earlier ISGlobal study projected could result in millions of deaths.
To address mounting debt burdens in donor countries and the global reallocation of resources toward military spending, the study’s authors propose alternative funding mechanisms rooted in international taxation.
Modeling Ten Fiscal Scenarios
The research models ten distinct fiscal scenarios involving multinational corporations, carbon emissions, cryptocurrency transactions, sovereign debt interest, financial transactions, and billionaire wealth.
Among the evaluated measures, a 3% annual tax on the wealth of cienmillonarios stands out as the most impactful. Implemented by 2026, the tax could mobilize enough resources by 2030 to prevent 29.5 million deaths globally, including 3.4 million among children. A more modest 1% levy on the same group would save an estimated millions of lives.
Alternative fiscal tools also show high yields. A financial transactions tax—levying a tax on operations exceeding €1 billion—could prevent a vast number of deaths, while a global minimum tax on multinational corporations could prevent around millions of deaths, according to the findings.
Wealth Concentration and Global Disparities
The study underscores stark global disparities, noting that the wealthiest 10% of the world’s population holds 75% of global wealth, while the bottom 50% commands just 2%. The planet currently counts 92,140 cienmillonarios.
International Arenas and Municipal Politics
The proposals build upon discussions held in international policy arenas, including the G20, the OECD/G20 Inclusive Framework on Base Erosion and Profit Shifting, and the Fourth International Conference on Financing for Development. During Brazil’s G20 presidency in 2024, economist Gabriel Zucman advanced proposals for a coordinated 2% tax on billionaires, highlighting that ultra-wealthy individuals often pay effective tax rates far below the scale of their total accumulated assets.
In the United States, policy discussions have included proposals such as a prospective 5% tax on billionaires in California, reflecting a wider domestic and international focus on wealth concentration. In Spain, data cited by researchers indicates that the wealthiest 1% of the population has expanded its share of total national wealth by six percentage points over the past five years, reinforcing calls among economists for structural tax reform to address rising inequality.
