Can indifference make the world greener?

We test whether people's tendency to stick with the default option can help save resources. In a natural field experiment we switch printers' default settings, from simplex to duplex printing, at a large Swedish university. The results confirm that roughly one third of all printing is determined by the default alternative, and hence daily paper consumption drops by 15 percent due to the change. The effect is immediate, lasts throughout the experimental period, and remains intact after six months. We also investigate how the more conventional method of encouraging people to save resources performs, and find it has no impact. Recent theoretical and empirical contributions indicate that the default effect works through recommendation, depends positively on the number of alternatives in the choice set, and is reinforced for difficult decisions. We demonstrate that the default option matter in a simple, non-dynamic, decision task with only two alternatives, and where people have been explicitly informed about the recommended course of action.