There may be a reason the rich are getting richer since the recession — they’re giving less of their money to charity than poorer Americans.

The wealthiest Americans — those who earned $200,000 per year and over — actually reduced the share of their income they gave to charity by 4.6% in 2012, compared to the amount they gave in 2006, according to a new analysis of Internal Revenue Service tax returns researchers at the Chronicle of Philanthropy, a Washington, D.C. periodical.

Americans took tax deductions on $180 billion of charitable donations in 2012, averaging 3% of total income and on a median income of $82,823 with a median contribution was $3,176. Those who earned less than $100,000 — including poor and middle-class families with two working adults — donated 4.5% more of their income in 2012 than 2006, but those making $25,000 or less gave 16.6% more.

In 2012, those earning less than $25,000 a year gave 7.7% of their income to charity, but that figure steadily declined as salaries increased to 4.6% (for those earning $25,000 and $50,000 per year), 3.5% ($50,000 to $75,000), 3% ($75,000 to $100,000), 2.6% ($100,000 to $200,000) and 2.7% (for people earning $200,000 or more), although some of the 1% have chosen to give away far more than that.

At least 30 billionaires have chosen to sign the “Giving Pledge,” an initiative started in 2009 to encourage the ultra-wealthy to give away half their wealth. (Warren Buffett has pledged to give away 99% of his wealth. He once told a television interviewer: “I want to give my kids just enough so that they would feel that they could do anything, but not so much that they would feel like doing nothing.”)

Nonprofit leaders say it was the loyalty of those with modest incomes that sustained them in the roughest periods of the recession and are the ones who continue to do so now that the economy is starting to recover. Tami Phillips, chief development officer at the Midnight Mission, a Los Angeles shelter, told the Chronicle: “It hits closer to home. Any day, they too could become homeless.”

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“Wealthy people tend to give to colleges, art museums, opera and hospitals very generously,” says Stacy Palmer, editor of The Chronicle of Philanthropy. “Fundraisers at those institutions are very sophisticated and go after wealthy people. Food banks depend more on lower income Americans. They know people who’ve lost their jobs and respond to appeals from social service organizations.”

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But wealthier Americans obviously contributed more overall dollars than low-income people, as even a smaller percentage of their income is usually worth more in total dollar value. The richest Americans donated $77.5 billion in 2012, an increase of $4.6-billion after adjusting for inflation. Those who earned less than $100,000 gave $57.3 billion in the same period, the report concluded.

So why to poorer people give more of their earnings than rich Americans? “They were digging deep to help their neighbors,” Palmer says. Wealthier Americans were obviously very nervous about the downturn in the economy and were more worried about their own personal future, she adds. “They may have been more directly affected by the stock market crash than other Americans,” she says.

The difference is a conundrum for social scientists too. People with a lower socioeconomic status typically have fewer resources, greater exposure to hardship, and reduced sense of personal control, according to a 2010 study, “Having Less, Giving More: The Influence of Social Class on Prosocial Behavior,” by psychology professors at the University of Toronto and University of California, Berkeley.

Given their more vulnerable place in society, people with less money could be expected to prioritize self-interest over the welfare of others. But the authors of the 2010 report had one theory: “By behaving generously and helping those in need, lower class individuals may promote trust and cooperation from others, thus ensuring that in times of hardship, their needs will, too, be met.”

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