MORE GENEROSITY NOW MEANS GREATER IMPACT LATER

Of course, deciding how much to give is a most personal choice — perhaps the most delicate issue in the philanthropic pantheon. But there are some hard-and-fast rules: Never feel pushed into giving more than you intend. Never be influenced by guilt. Never make a decision based on someone else’s gift.

On average, Americans give 2% to 4% of their income to charity, although many people, not only the rich, give a whole lot more. Unsurprisingly, high–net worth households have the greatest impact. They are responsible for two-thirds of all household charity in the country, according to a recent survey conducted for Bank of America by the Center on Philanthropy at Indiana University. The survey defined high–net worth households as those with annual incomes of at least $200,000 or net worths of at least $1 million.

People with even more money seem to give proportionately less, according to another study, by an organization called the New Tithing Group. Claude Rosenberg, who died in 2008 at age 80, launched this San Francisco private foundation in the late 1990s (which folded after he died). He had earned a fortune as a fund manager and spent the last decades of his life trying to persuade wealthy people to increase their charitable giving and thus whittle their tax bill. Rosenberg argued that charitable giving is limited because most Americans — and pointedly the wealthiest ones — make donations based on a percentage of income, which is what tax accountants and other financial advisors typically recommend.

So, based on giving as a percentage of income, relative to what they can afford, poor and middle-class people give more than the wealthy do. In 2005, for example — the year New Tithing did its study — taxpayers with incomes of $10 million or more and average assets of $125 million allocated only about 1.4 percent of their investable assets to charity. Rosenberg called this the “eyeballing-lowballing syndrome.” That is, people of means frequently “eyeball” their incomes to decide how much to donate to charity. But since their guesses about what they can actually afford are very rough, they usually “lowball” their gifts.

Overall, Rosenberg thought we could all afford to give more if we reckoned our giving capacity based on net worth rather than yearly income. And giving more now rather than waiting until you’re older and perhaps richer, or until your estate makes a bequest in your will likely means significantly greater rewards for your chosen cause. That’s because unaddressed social ills, as we all know, tend to worsen over time. Whatever problem you’re trying to resolve is bound to turn more severe as time passes. Plus, the inevitable march of inflation means that today’s dollar buys more value than tomorrow’s dollar can. Even so, the majority of donors earmark the same amount for charity every year, without adjusting for the effects of inflation.

All in all, says the Rosenberg Rule, as some have dubbed it, the smart move is to give today rather than tomorrow.