Want folks to use reusable mugs? Give them a chance to win free coffee: UBC researchers

Psychology researchers found by turning rewards for using a reusable mug into a game of chance rather than a discount, people will play.

University of B.C. researchers put all their chips in on a bet that offering students a one-in-10 chance of a free coffee would change their single-use cup habits.

And they won.

The researchers, from UBC’s psychology department and the Institute for Resources, Environment and Sustainability, say a chance at a free coffee works better than a discount to encourage people to bring in their reusable mugs at coffee shops.

It’s a win-win, say researchers: Students get a chance at a free cup of Joe while being more environmental and the shops brew up more business.

For the field study, which was conducted at two Loafe Café locations on campus, customers with reusable cups were offered a 10 per cent chance to win a free coffee. One café was a control site and the other the study site.

Reusable cup usage more than doubled at the study site when the chance to win a free coffee was offered, according to the study, which was conducted at coffee shops at the UBC campus, where most still charge a 25-cent fee for single-use disposable cups. This is despite the fact that Vancouver has repealed the fee (UBC isn’t part of the city of Vancouver.)

How the game was played

Researchers provided reward tracking sheets to the café staff, with each row containing one coffee icon randomly placed among nine empty boxes.

Every time a customer brought their own reusable cup, the staff would mark one box on the tracking sheet (going from left to right, top to bottom). If the coffee icon was marked, the staff would provide a free coffee to the customer who brought their own reusable cup.

The tracking sheets were kept behind the counter and never revealed to the customers, according to the study.

It’s that ‘Me Espresso’

Lead researcher Dr. Jiaying Zhao, an associate psychology professor at UBC, says it’s the high that comes from a possible win that attracts people, who generally prefer low-probability large rewards over small certain rewards.

“You say, ‘Oh I have a decent chance of getting a free coffee.’ And that’s the exciting part,” said Zhao, adding that not only is the chance more favourable than the fee reduction of 25 cents, but it’s also preferred to the coffee-stamp-card reward system.

“Personally I don’t like stamp cards because I hate carrying that in my wallet. Also, it’s so boring. You have to collect 10 or 11 stamps before you get a free coffee.”

The buzz on reusable mugs

Every year, between 250 billion and 300 billion single-use disposable cups are used globally, according to the study.

“This causes significant environmental and health problems because we are ingesting microplastics. It’s so terrible for our health so we need to get away from using them,” said Zhao.

Studies show microplastics can accumulate in living organisms, which can cause detrimental health problems such as developmental delays, cardiovascular diseases and gastrointestinal disorders.

“They also make no financial sense because it only takes a month or less to make up the cost of the reusable cup. I guess people like the convenience so it is very hard to get rid of them.”

Full steam ahead

Up next for researchers is a study on how this could work for other eco-friendly actions like plastic packaging, said Zhao.

“We would love to try to team up with a service that uses reusable containers, businesses who are willing to work with us on getting rid of single-use items, to get people to use more reusable. So that’s the next step.”

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