In a New York Times op-ed on August 14 2011, Berkshire Hathaway chief executive Warren Buffett wrote that the US should “stop coddling the super-rich” and called for tax rates to be raised “immediately on taxable incomes in excess of $1m, including, of course, dividends and capital gains”. The next morning, at a televised “town hall” meeting in Cannon Falls, Minnesota, President Barack Obama praised Mr Buffett’s intervention. A few weeks later a “Buffett rule”, requiring that millionaires pay higher taxes as a share of their incomes than middle-class Americans, featured in the budget plan the president sent to Congress.

What Mr Buffett actually proposed would, notably, have a trivial impact on his own tax bill. This is because the “taxable income” he refers to is a minuscule portion of his total income – amounting to less than 1 per cent of his income held within Berkshire Hathaway, of which he owns 22 per cent.

Mr Buffett’s share of Berkshire’s 2010 pre-tax income was a whopping $4.2bn, taxes on which amounted to more than $1.2bn – a 29 per cent rate. This income would be subject to tax again at the personal rate if it was taken out of the company but since Mr Buffett has pledged to give away his fortune he would avoid the tax he wants to increase. At the Berkshire annual meeting in 2010, Mr Buffett urged fellow shareholders to “follow my tax-dodging example”.