The Little Book of Green Nudges

CASE STUDIES: UNINTENDED CONSEQUENCES

When the University of Hong Kong stopped the use of some disposable plastic items on campus, there was reduced consumption of these items but also a partial switch to different disposable items such as paper containers. To tackle this, the university is encouraging staff and students to adopt bring-your-own habits, including discounts for people who use their own containers at campus catering outlets, and a “BYO week” in collaboration with all other universities in Hong Kong. The Technical University of Denmark introduced meat-free days in campus canteens. But then it found that more people ate at street food stalls on campus that sold meat, which had the additional consequence of greater use of single-use packaging and cutlery. In response, the canteens changed the nudge to feature less meat rather than no meat. Canteen sales returned to their previous levels, so this adjustment appears to have brought customers back.

often shift to match our behaviour, so nudges to change behaviour can help build support for engagement. On the other hand, if we substitute a new behaviour for the old one, that new behaviour might have undesirable effects (see case studies). Consider the whole population: Might certain parts of the population be affected differently by your nudge? Make sure to check the outcomes for people of different genders, cultures and other groups.

Students at the University of Hong Kong fill up their reusable containers.

The Little Book of Green Nudges 39