Think Like a Freak

by Steven D. Levitt

So if you are the person designing an incentive scheme, you can use this knowledge to herd people into doing the right thing—even if they’re doing it for the wrong reasons. With any problem, it’s important to figure out which incentives will actually work, not just what your moral compass tells you should work. The key is to think less about the ideal behavior of imaginary people and more about the actual behavior of real people. Those real people are much more unpredictable. Consider another Robert Cialdini experiment, this one at Petrified Forest National Park in Arizona. The park had a problem, as it made clear on a warning sign: YOUR HERITAGE IS BEING VANDALIZED EVERY DAY BY THEFT LOSSES OF PETRIFIED WOOD OF 14 TONS A YEAR, MOSTLY A SMALL PIECE AT A TIME. The sign plainly appealed to the visitors’ sense of moral outrage. Cialdini wanted to know if this appeal was effective. So he and some colleagues ran an experiment. They seeded various trails throughout the forest with loose pieces of petrified wood, ready for the stealing. On some trails, they posted a sign warning not to steal; other trails got no sign. The result? The trails with the warning