By Heather Stewart / The Observer

The world’s super-rich have taken advantage of lax tax rules to siphon off at least $21 trillion, and possibly as much as $32tn, from their home countries and hide it abroad – a sum larger than the entire American economy.

James Henry, a former chief economist at consultancy McKinsey and an expert on tax havens, has conducted groundbreaking new research for the Tax Justice Network campaign group – sifting through data from the Bank for International Settlements (BIS), the International Monetary Fund (IMF) and private sector analysts to construct an alarming picture that shows capital flooding out of countries across the world and disappearing into the cracks in the financial system.

Comedian Jimmy Carr became the public face of tax-dodging in the UK earlier this year when it emerged that he had made use of a Cayman Islands-based trust to slash his income tax bill.

But the kind of scheme Carr took part in is the tip of the iceberg, according to Henry’s report, entitled The Price of Offshore Revisited. Despite the professed determination of the G20 group of leading economies to tackle tax secrecy, investors in scores of countries – including the US and the UK – are still able to hide some or all of their assets from the taxman.

“This offshore economy is large enough to have a major impact on estimates of inequality of wealth and income; on estimates of national income and debt ratios; and – most importantly – to have very significant negative impacts on the domestic tax bases of ‘source’ countries,” Henry says.

Using the BIS’s measure of “offshore deposits” – cash held outside the depositor’s home country – and scaling it up according to the proportion of their portfolio large investors usually hold in cash, he estimates that between $21tn (£13tn) and $32tn (£20tn) in financial assets has been hidden from the world’s tax authorities.

“These estimates reveal a staggering failure,” says John Christensen of the Tax Justice Network. “Inequality is much, much worse than official statistics show, but politicians are still relying on trickle-down to transfer wealth to poorer people.

“This new data shows the exact opposite has happened: for three decades extraordinary wealth has been cascading into the offshore accounts of a tiny number of super-rich.”

Read more from The Guardian: http://www.guardian.co.uk/business/2012/jul/21/offshore-wealth-global-economy-tax-havens