Gold star stickers on trash bins increase recycling rates

What unsustainable behavior needs to change:

Aotearoa New Zealand sadly isn’t amongst the world champions of recycling. Compared to other countries, recycling rates are much lower. According to Recycling New Zealand, in Auckland alone, the amount of waste sent to landfills is expected to double in the next 10 years!

More numbers? 

• NZ generates 17 million tons of waste each year, while 76% of it goes into landfills 
• 40% of household waste that could be recycled, goes into the wrong bin
• Each year, approximately 2 billion plastic containers aren’t getting recycled

Following the lockdown of the COVID19 pandemic, recycling rates worsened. In Christchurch particularly, rates plummeted, with material from only 48% of garbage collection trucks being recycled in June 2020. The reason: too much contamination resulting from poor sorting by residents. Even the local EcoSort facility had to close temporarily due to  many residents failing to, for example, remove bottle lids or exclude thin plastic films, such as cheese wrappers. 

The question was: How to motivate people to better sort their garbage and keep recycling streams clean? Punishment or reward? Sticks or carrots?

The Green Nudge:

The Christchurch city council introduced a public reward (and shaming) system that builds on the idea of social norms. Anyone who does an excellent job at sorting the right, properly cleaned rubbish items gets a large gold star added to their kerbside recycling bin, visible for the whole neighbourhood to see. The star uses a neat pun, saying: “Thanks for bin great”. 

The result: In 2020, more than 177,000 bins have been checked, with nearly 50,000 gold stars issued (~31%). They not only rewarded successful recyclers – compliance staff also gave out education notices (to ~61%) and removed the bins of those who repeatedly failed to recycle properly (only ~260 in total). The council considers the Green Nudge initiative as a great success: In only a few months, the number of successful recycling trucks headed to the sorters increased from 48% to 80%.

So, what are the underlying reasons that the nudge worked? We’ve seen other social imitation nudges like in the energy supplier or shopping trolley examples. But the gold star stickers are more visible on a public level and have a stronger shaming element.

MIT research scientist Erez Yoeli, who studies how altruism works, would probably explain this as ‘our collective desire to be seen as generous and kind instead of being selfish’. But Kenrick and Griskevicius might argue that “going green to be seen” might indeed be status-driven social signalling and thus be anything but altruistic.

Full article in The Guardian.