Why people donate?

Economics focus

Looking good by doing good
Jan 15th 2009
From The Economist print edition

Rewarding people for their generosity may be counterproductive

Illustration by Jac DepczykA LARGE plaque in the foyer of Boston’s Institute for Contemporary Art (ICA), a museum housed in a dramatic glass and metal building on the harbour’s edge, identifies its most generous patrons. Visitors who stop to look will notice that some donors—including two who gave the ICA over $2.5m—have chosen not to reveal their names. Such reticence is unusual: less than 1% of private gifts to charity are anonymous. Most people (including the vast majority of the ICA’s patrons) want their good deeds to be talked about. In “Richistan”, a book on America’s new rich, Robert Frank writes of the several society publications in Florida’s Palm Beach which exist largely to publicise the charity of its well-heeled residents (at least before Bernard Madoff’s alleged Ponzi scheme left some of them with little left to give).

As it turns out, the distinction between private and public generosity is helpful in understanding what motivates people to give money to charities or donate blood, acts which are costly to the doer and primarily benefit others. Such actions are widespread, and growing. The $306 billion that Americans gave to charity in 2007 was more than triple the amount donated in 1965. And though a big chunk of this comes from plutocrats like Bill Gates and Warren Buffett, whose philanthropy has attracted much attention, modest earners also give generously of their time and money. A 2001 survey found that 89% of American households gave to charity, and that 44% of adults volunteered the equivalent of 9m full-time jobs. Tax breaks explain some of the kindness of strangers. But by no means all.

Economists, who tend to think self-interest governs most actions of man, are intrigued, and have identified several reasons to explain good deeds of this kind. Tax breaks are, of course, one of the main ones, but donors are also sometimes paid directly for their pains, and the mere thought of a thank-you letter can be enough to persuade others to cough up. Some even act out of sheer altruism. But most interesting is another explanation, which is that people do good in part because it makes them look good to those whose opinions they care about. Economists call this “image motivation”.

Dan Ariely of Duke University, Anat Bracha of Tel Aviv University, and Stephan Meier of Columbia University sought, through experiments, to test the importance of image motivation, as well as to gain insights into how different motivating factors interact. Their results, which they report in a new paper*, suggest that image motivation matters a lot, at least in the laboratory. Even more intriguingly, they find evidence that monetary incentives can actually reduce charitable giving when people are driven in part by a desire to look good in others’ eyes.

The crucial thing about charity as a means of image building is, of course, that it can work only if others know about it and think positively of the charity in question. So, the academics argue, people should give more when their actions are public.

To test this, they conducted an experiment where the number of times participants clicked an awkward combination of computer keys determined how much money was donated on their behalf to the American Red Cross. Since 92% of participants thought highly of the Red Cross, giving to it could reasonably be assumed to make people look good to their peers. People were randomly assigned to either a private group, where only the participant knew the amount of the donation, or a public group, where the participant had to stand up at the end of the session and share this information with the group. Consistent with the hypothesis that image mattered, participants exerted much greater effort in the public case: the average number of clicks, at 900, was nearly double the average of 517 clicks in the private case.

However, the academics wanted to go a step further. In this, they were influenced by the theoretical model of two economists, Roland Benabou, of Princeton University, and Jean Tirole, of Toulouse University’s Institut d’Economie Industrielle, who formalised the idea that if people do good to look good, introducing monetary or other rewards into the mix might complicate matters. An observer who sees someone getting paid for donating blood, for example, would find it hard to differentiate between the donor’s intrinsic “goodness” and his greed.

Blood money
The idea that monetary incentives could be counterproductive has been around at least since 1970, when Richard Titmuss, a British social scientist, hypothesised that paying people to donate blood would reduce the amount of blood that they gave. But Mr Ariely and his colleagues demonstrate a mechanism through which such confounding effects could operate. They presumed that the addition of a monetary incentive should have much less of an impact in public (where it muddles the image signal of an action) than in private (where the image is not important). By adding a monetary reward for participants to their experiment, the academics were able to confirm their hypothesis. In private, being paid to click increased effort from 548 clicks to 740, but in public, there was next to no effect.

The trio also raise the possibility that cleverly designed rewards could actually draw out more generosity by exploiting image motivation. Suppose, for example, that rewards were used to encourage people to support a certain cause with a minimum donation. If that cause then publicised those who were generous well beyond the minimum required of them, it would show that they were not just “in it for the money”. Behavioural economics may yet provide charities with some creative new fund-raising techniques.



*”Doing Good or Doing Well? Image Motivation and Monetary Incentives in Behaving Prosocially”, by Messrs Ariely, Bracha and Meier. Forthcoming in American Economic Review, March 2009.