The $21trn figure was described as being the size of the US and Japanese economies combined.
The Price of Offshore Revisited was written by James Henry, a former McKinsey chief economist, and released exclusively to the UK’s Observer newspaper on Sunday.
In the report, Henry “shows that at least £13tn – perhaps up to £20tn – has leaked out of scores of countries into secretive jurisdictions such as Switzerland and the Cayman Islands with the help of private banks, which vie to attract the assets of so-called high net-worth individuals,” the Observer article reports.
“Their wealth is, as Henry puts it, ‘protected by a highly paid, industrious bevy of professional enablers in the private banking, legal, accounting and investment industries taking advantage of the increasingly borderless, frictionless global economy’. "
The report finds that the world’s top 10 private banks, including institutions that have been the spotlight of US and UK tax authorities recently, such as Switzerland’s UBS, as well as the US investment bank Goldman Sachs, “managed more than £4tn in 2010, a sharp rise from £1.5tn five years earlier”, the Observer points out.
Some scepticism
Interviewed by the BBC, tax expert and government adviser John Whiting said he was sceptical of the scale of assets said to be hidden.
"There clearly are some significant amounts hidden away, but if it really is that size, what is being done with it all?" the BBC quotes Whiting, director of the Office of Tax Simplification, as saying.
To read a summary of the report’s findings on the Tax Justice Network’s website, click here.
