Nudging to Reduce Littering at Events In Uppsala

Valborg celebrations in Uppsala are among Sweden’s largest, attracting thousands of participants every year. However, the event comes with a recurring challenge: large amounts of litter left behind. In 2023, 12,878 kilos of trash were collected during and after the event, but only 48% (6,158 kilos) of the total amount was collected on Valborg Day itself, meaning that most of the trash had to be collected by the city on the day after the event.

For 2024, Nudgd, in collaboration with Destination Uppsala, Pantamera, Akademiska Hus, and Länsförsäkringar, set a shared goal to improve recycling practices and encourage more attendees to dispose of their waste responsibly on Valborg Day itself, rather than leaving it behind to be collected after the event. With the goal to reduce environmental impact as well as cleanup costs for the municipality.

To address these challenges, we implemented solutions combining behavioral science with practical interventions:

• Trash bags were distributed by volunteers to make waste management easier.
• New trash bag stations were set up where attendees could grab bags and dispose of waste.
• Additional sorting bins were placed in visible locations to simplify proper waste disposal.
• A “trash cam” added an element of fun and leveraged social proof. Inspired by the “kiss cam” at sports events, the camera broadcasted live footage of attendees disposing of their trash on a large screen, inspiring others to follow suit.

To further motivate participants, our collaborators donated 1 SEK per kilo of trash collected to the Uppsala Akademiska Children’s Hospital.

Although fewer people attended Valborg in 2024, 9,820 kilos of trash were collected during and after the event. The amount of waste taken care of on Valborg Day itself increased by 18.8% compared to 2023. Waste sorting also saw a significant improvement, highlighting that the interventions made a difference.

Together, we’ve shown how small behavioral shifts can lead to significant impacts. Nudges can be simple, and yet effective.