There is growing concern at the toll which tax havens are taking on economies, government budgets and inequality worldwide as recent research shows they may conceal the equivalent of 10% of global output and nearly a third of the wealth of individuals with a net worth of more than $45m.
The estimates may be conservative. At least 366 companies in the Global Fortune 500 index operate one or more subsidiaries in tax haven countries, according to a 2017 report by the Institute on Taxation and Economic Policy, a Washington-based think tank.
The size of assets held in these tax havens could amount to more than $21tr.
Analysis from researchers in Denmark and the US showed that just 11 tax havens absorbed $616bn in corporate profits last year alone, as companies used legal loopholes to move money away from more costly domestic tax regimes.
The impact of tax evasion is most severe