In an episode​ of Seinfeld from 1996, Kramer and Newman hatch an ingenious moneymaking scheme. In New York, where they live, bottles and cans can be recycled for five cents each, but in Michigan the refund is ten cents. They realise that if they collect bottles in New York and take them to Michigan, they can double their money. Kramer spots a hitch: transport costs, including petrol and tolls, would exceed the nominal profit. But then they realise they can save on petrol by using Newman’s work vehicle, a postal truck. It’s on.In the event, the scheme falls apart in slapstick fashion. In reality, it wouldn’t have worked anyway: Michigan law requires bottles and cans to be purchased in-state to be eligible for refund. But there is certainly potential for what we might call waste arbitrage. If the fees involved in recycling or disposing of waste are different in different places, you can in theory move waste from one place to another to exploit that difference. You can even make a business out of it.Waste Wars, Alexander Clapp’s new book, is about such businesses. In the 1980s, waste became a national export across much of the global North. Since then, firms have made vast amounts of money by sending the rich world’s waste to the global South. At first, the focus of this business was hazardous waste like asbestos or paint sludge. In countries like the US it cost as much as $250 per tonne to bury hazardous waste domestically at a time when the price of burying it in many African countries was less than $3 per tonne. Even after shipping costs, American companies could save around $200 per tonne by sending their waste overseas. In 1991, a leaked memorandum on trade liberalisation sent by Larry Summers, then chief economist at the World Bank, stated that ‘the economic logic behind dumping a load of toxic waste in the lowest wage country is impeccable and we should face up to that.’In fact, so much money could be saved by exporting toxic waste that rich countries and firms