Hertie School students apply cutting-edge research to reduce waste

Christian Traxler challenged his students to identify problems at the Hertie School and design nudges to address them.

If you ever find yourself in the men’s bathroom at the Schiphol Airport in Amsterdam, you are likely to notice a small etching of a fly inside the urinals. What you may not realize is that the presence of this fly, by subtly influencing behaviour, has reduced total spillage at the urinal by 80%. This is a famous example of what Cass Sunstein and Richard Thaler call a “Nudge”.

Nudges are changes in the “choice architecture” that aim at affecting behaviour without resorting to traditional regulatory interventions. Increasingly, governments are recognizing the value of nudges for society. For example, the UK’s “Behavioural Insights Team” undertakes research to employ evidence-based behavioural policy interventions. In Germany the last coalition agreement paved the way for establishing a similar sort of “Nudge Unit”. At the Hertie School, Professor of Economics Christian Traxler recently launched the event series “Behavioural Insights”, which aims at shedding more light on the pros and cons of applying behavioural insights to policy-making.

In Professor Traxler’s class, Behavioural Economics and Experimental Policy Analysis, he challenged his students to identify problems at the Hertie School and to design nudges that addresses these problems. Several approaches were then implemented in randomized control trials that allowed for rigorous tests of the nudges’ effectiveness.

One group of students focused on the problem of paper towel overuse in the school’s bathrooms. To reduce waste and conserve resources at the Hertie School, they introduced a sticker on the paper towel dispensers. The signs read: “The majority of Hertie School students uses at most two paper towels” and pictured a pair of hands, carefully pulling a paper towel from the dispenser. Over four weeks, the students introduced the nudge in a staged way and measured the daily paper towel usage at the campus’ bathrooms with and without the stickers.

The result of the school-wide experiment was presented last week in an open class. The students found a sizable response to their intervention: Relative to the untreated control bathrooms, the nudge induced a drop in paper towel consumption by approximately 20 percent. The effect was equally observed at both male and female bathrooms.

“I am very impressed with the high level of scientific methodology the students applied in their research,” says Professor Traxler who supervised the experiment. “They have achieved a remarkable result which demonstrates the power of nudges - no matter on which level.” The days when flies were the only prominent bathroom nudges seem to be gone.