TO encourage city dwellers to throw away less and be more mindful about what they put in the garbage, some cities tax their residents according to the amount of waste they produce. This policy has been implemented in several American states, as well as in Seoul, Korea to reduce food waste.

"Pay-as-you-throw." In other words, if you produce waste you will take out your wallet. A policy that may seem somewhat punitive. But it's being adopted in many cities around the world. And it seems to be paying off.

In the United States, the practice is widespread, with cities such as Seattle, Berkeley, Austin and Portland using it. The principle is simple, since it consists, in most cases, of paying additional taxes according to individual waste production. "Pay-as-you-throw is one of local governments' most effective tools for reducing waste, controlling waste disposal costs and giving residents an incentive to participate in recycling and composting programs," outlines research published in The Conversation.

This is the case in the US state of Massachusetts, where households generated an average of 562 kilograms (1,239 pounds) of waste per household in 2020, compared with 796 kilograms (1,756 pounds) per household in cities that have not adopted this approach, says the paper by Lily Baum Pollans, assistant professor of urban policy and planning at Hunter College in New York.

So how does it work?

Some municipalities require residents to label garbage bags so that they pay separately for each package containing the garbage. They may also be required to register for a garbage collection service, which limits the amount of garbage they can put out on the curb.

That's the kind of system that has been set up in Seoul. Since 2013, the capital of South Korea has required its residents to pay additional taxes based on the weight of their food waste. Each household has a smart card, the key to accessing the connected waste garbage cans equipped with scales and provided by the municipality.

Once the contents of the (biodegradable) garbage bags are emptied, the weight of the waste is displayed on a small screen. The relevant charges are then added to the bill of the household that holds the card. A compulsory  pay system that encourages residents to reduce food waste and that has allowed the Seoul municipality to save about 7 million euros in terms of garbage collection.

Cryptocurrency in exchange for waste

Other strategies are orchestrated to encourage city dwellers to pick up litter in their spare time. While some take part in "plogging" (a Swedish trend that consists of jogging with a garbage bag in hand while picking up litter along the way), others do so in exchange for financial compensation.

Specifically, this is the modus operandi of the Clean Coins app, developed by a startup based in Haifa, Israel. The startup has created an eponymous cryptocurrency to reward users for collecting waste in the city. Users are rewarded according to the amount of waste they collect and can spend their earnings (exclusively in cryptocurrency) at the company's partner stores.