It's a paradox that seems to reinforce every stereotype about greed and wealth: those with the smallest incomes donate the greatest share of their money, while the rich pinch their pennies. Among taxpayers who claim a deduction for their generosity, the proportion of money given away by low-income earners is 11 times higher than that of wealthy taxpayers.

The disparity, highlighted in a Fairfax analysis of the most recent data available (2010-11) from the Tax Office, shows those who claimed tax-deductible gifts in the lowest taxable income band - less than $6001 - donated an average of 22 per cent of their incomes. By contrast, taxpayers reporting $1 million or more of taxable income donated an average of 1.8 per cent of their income.

"Some people say this proves that low-income earners are more generous than high-income earners," says Myles McGregor-Lowndes, director of the Centre of Philanthropy and Non-profit Studies at Queensland University of Technology. But other factors, including wealthy retirees, may be at play.

"We suspect that it's to do with high net-worth individuals who may not have any income or little income but give away substantial amounts so they don't have to pay income tax."

The affluent gain more from charitable deductions than low-income earners. In 2010-11, tax-deductible donations returned more than $1 billion to taxpayers, 20 per cent of which went to the wealthiest 1 per cent.