Gabriel Zucman

This policy note provides a revenue estimate of how much European Member States could raise with a minimum tax of 2% or 3% on the wealth of people owning more than €100 million or €1 billion in wealth – the scenarios considered in the report commissioned by the G20 presidency.

In the second half of the 2010s more than 100 countries — including all large offshore financial centers — started to automatically exchange bank information with foreign tax authorities. This informational big-bang marks a break with the situation of offshore bank secrecy that prevailed before. We study its effects on tax compliance by analyzing the universe of information reports sent by foreign banks to Danish authorities, matched to population-wide micro-data on income, wealth, and cross-border bank transfers. In response to the automatic exchange of bank information, tax evaders may repatriate previously undeclared offshore wealth, they may start to self-report offshore income to the tax authorities, or the tax authorities may detect their evasion in audits that use the new information reports. Using a variety of research designs, we find large compliance effects along all these margins, with the largest response coming from repatriation of wealth. Overall we estimate that the automatic exchange of bank information has closed about 70% of the offshore tax gap. These results highlight the power of international cooperation to improve tax compliance: tax evasion is not a law of nature in a globalized world.

This report presents a proposal for an internationally coordinated standard ensuring an effective taxation of ultra-high-net-worth individuals. In the baseline proposal, individuals with more than $1 billion in wealth would be required to pay a minimum amount of tax annually, equal to 2% of their wealth. This standard could be flexibly implemented by participating countries through a variety of domestic instruments, including a presumptive income tax, an income tax on a broad notion of income, or a wealth tax. The report presents evidence that contemporary tax systems fail to tax ultra-high-net-worth individuals effectively, clarifies the case for international coordination to address this issue, analyzes implementation challenges, and provides revenue estimations. The main conclusions are that (i) building on recent progress in international tax cooperation, such a common standard has become technically feasible; (ii) it could be enforced successfully even if all countries did not adopt it, by strengthening current exit taxes and implementing “tax collector of last resort” mechanisms as in the coordinated minimum tax on multinational companies; (iii) a minimum tax on billionaires equal to 2% of their wealth would raise $200-$250 billion per year globally from about 3,000 taxpayers; extending the tax to centimillionaires would add $100-$140 billion; (iv) this international standard would effectively address regressive features of contemporary tax systems at the top of the wealth distribution; (v) it would not substitute for, but support domestic progressive tax policies, by improving transparency about top-end wealth, reducing incentives to engage in tax avoidance, and preventing a race to the bottom; (vi) its economic impact must be assessed in light of the observed pre-tax rate of return to wealth for ultra-high-net-worth individuals which has been 7.5% on average per year (net of inflation) over the last four decades, and of the current effective tax rate of billionaires, equivalent to 0.3% of their wealth.

This note presents new evidence on the scale of foreign investment in the Dubai residential property market. Using new data comprising the ownership of a large share of the Dubai property market, we present updated estimates of foreign-owned real estate for the years 2020 and 2022. We find that foreign nationals hold around 43% of the total value of all residential property in the city. Foreign-owned residential real estate grew by 20%—around $ 23 billion—between the beginning of 2020 and early 2022. We also find evidence of a substantial boom in Russian interest in the city following the invasion of Ukraine, with both utility accounts and residential leases associated with Russian nationals increasing sharply. Relying on simple assumptions to allocate new property purchases across nationalities, we conservatively estimate that Russians bought up to $2.4 billion worth of existing properties and a further $3.9 billion of in-development properties since the invasion. Our findings have three main policy implications: 1. Anti-money laundering organisations such as the Financial Action Task Force should intensify pressure on the United Arab Emirates to clean up its real estate sector 2. Automatic exchange-of-information regimes such as the OECD’s Common Reporting Standard (CRS) should be expanded to include real estate 3. Policymakers should begin the process of introducing the building blocks of a global asset registry, to build a unified picture of non-financial and financial assets, first at the regional level, then at the global level Our updated 2020 estimates are also now available on the Atlas of the Offshore World.