Opinion: ‘Fast’ and ‘Slow’ Thinking Affects How Donors Give

New research on giving indicates that statistical measures of a charity’s effectiveness tend to attract large donors but turn off smaller contributors, offering nonprofits clues on tailoring appeals for particular audiences, a Bloomberg View columnist writes.

Cass R. Sunstein, a Harvard law professor, says the report by economists at Yale and Clemson universities reflects psychologists’ notion of fast and slow thinking½the former intuitive and emotional, the latter more deliberate.

The study involved direct mailers for an antipoverty charity, some of which included a paragraph with detailed data on the group’s effectiveness. The numbers-heavy appeal produced more and higher donations from people who had frequently given more than $100 to the group, fewer and lesser gifts from smaller donors.

Mr. Sunstein says there was no net effect on donations in the experiment, with losses from small donors essentially canceling out gains from big ones. “For charities, as for institutions of many different kinds, the central lesson is clear: Statistical information might have a major impact on some people, but to others, it might be irrelevant—or even counterproductive,” he writes.