What supermarkets can do to reduce plastic waste

McCann Manchester's Carl Dunbar wrote this essay as part of the IPA's Applied Behavioural Economics course.

We are spotlighting some of the best essays from our MIPA qualifying courses and qualifications. Here, McCann Manchester's Carl Dunbar looks at how behavioural science could be used to help supermarkets encourage consumers to increase plastic recyling as part of the IPA's Applied Behavioural Economics course.

Seventy years ago the world’s annual consumption of plastic materials stood at around 5 million tonnes. Today, in the UK alone, it’s estimated that we waste nearly 5 million tonnes of plastic in just a single year.

The grocery sector is the largest user of consumer plastic packaging in the UK, accounting for over half of the 1.5 million tonnes of packaging used in retail every year. The top 10 UK supermarkets place over 810,000 tonnes of single-use plastic on the market. This is an issue now firmly in the public consciousness: plastic waste is set to beat price as UK customers' top concern when shopping.

Whilst most major supermarkets have committed to eliminating non-recyclable plastic packaging by 2025, most families still throw away about 40kg of plastic per year which could otherwise have been recycled. Eliminating non-recyclables is not enough: supermarkets must play help ensure the plastic that can be recycled makes its way back to the shops from the consumer.

The actions of Supermarkets can have a powerful impact on consumer behaviour.

The 5p plastic bag charge led to an 80% reduction in single-use carrier usage. That such a relatively small fee can prompt such a big change shows how small tweaks can make an exponentially bigger difference to behaviour.

Supermarket’s efforts to combat the environmental damage of plastic packaging are yet to take off. Sainsbury’s latest trial, titled ‘pre-cycling’, offers the customer the option to recycle unwanted packaging before leaving the store. This is done through the introduction of clearly labelled recycling bins by the checkouts.

On a purely rational level, the customer’s ability to remove unwanted packaging from goods straight away helps make it an instant habit and saves the customer the time spent sorting through recycling at home. However, reviewing against the Behavioural Economics EAST framework, you can see why it hasn’t taken off.

It’s not ‘Easy’ or ‘Timely’, as the customer has to go back through the shopping that they have just invested time packing. And it’s difficult for the single bin to gain ‘Social’ traction, as only one customer at a time can drop off their packaging, with no chance to demonstrate social proofing (unless an unlikely queue starts forming.)

Using three of the four principles of the EAST framework, we can start exploring alternative initiatives that could help find the next 5p-carrier-bag-scheme for the recycling conundrum.


Confusing and disparate labelling methods in the UK add to the challenge facing customers in knowing what to recycle. Not knowing which materials can be recycled or how their local scheme works is one of the main barriers to customer’s recycling efforts.

It’s an understandable barrier; plastic is usually colourless, and only by navigating the small logos on the packaging and knowing the local schemes can someone be sure what’s recyclable. Simplifying the labelling system would make the identification process easier. For example, a traffic light system, similar to that introduced by the food standards agency to warn of unhealthy foods, would give customers a quick, recognisable identifier. Green could mean wildly recyclable, Yellow for recyclable in certain local areas and Red for non-recyclable.

The more this system could be standardised across supermarkets, as with the food standards health warnings, the more habitual the behaviour could become.


Another key barrier to recycling is the act isn’t a directly rewarding experience in its own right. It takes effort on the part of the consumer to sort through and the benefit to the planet as a collective is at an unseen, macro level. Plastic exchange schemes, where customers are given financial incentives in exchange for plastic, offer a more direct reward, but the poor effort-to-gain ratio usually makes it undesirable.

Harnessing what we know from Behavioural Economic principles, financial rewards could be reframed to be more powerful. Evolving Sainsbury’s ‘pre-cycling’ example, if the post-till collection bins contained an incentive whereby for each drop off the customer was entered into a competition to win a money-off-your-shop voucher, the relatively high prize would be seen as more directly desirable reward. Winning vouchers could be handed out on the spot with a loud commotion to celebrate the win, for the benefit of those passing by, to build social proofing.


When people are busy they often struggle to establish a routine for sorting out recycling. Often this means forgetting to put the bin out on the scheduled collection days. This is where supermarkets could step in. Most know their customer’s postcode from their loyalty scheme data. Matching a customer’s postcode with their local area bin collection schedule, supermarkets could send email reminders on the day before bin collection, to help prompt habitual behaviour.

The emails could even provide a helpful prompt about what types of their packaging can be recycled, even using the loyalty card transactional data to show which specific packages the customer bought should be included in the plastic recycling bin the next day.
These relatively simple changes could drastically reduce the amount of would-be recyclable plastic making its way into landfill. But the benefits of recycling plastic will only take the planet so far. Unlike Glass and Cardboard, Plastic can only be recycled a certain number of times, meaning recycling will only help prevent damage to our environment up to a point.

The simplest and only real way to reduce plastic waste is to remove the need for customers to be active part of the recycling process: by removing plastic packaging altogether.

Real change will come by embracing the new trend of ‘refill shops’, where customers are forced to bring their own containers and fill food from large unpackaged tubs. How to implement this at scale and ultimately make this behaviour more desirable than purchasing pre-packaged goods will be the next social challenge for Behavioural Economics to lend its hand.

Carl Dunbar is an Account Director at McCann Manchester. This essay was a part of the IPA's Applied Behavioural Economics course, which is next running in London in May and champions a different social cause in each city.

For more on sustainability check out the IPA's 'Advertising and the climate crisis' session at AdWeek Europe.
Last updated 01 May 2024