Economics is the mother tongue of public policy, - Kate Raworth

Below the Doughnut’s social foundation lie shortfalls in human well-being, faced by those who lack life’s essentials such as food, education and housing. Beyond the ecological ceiling lies an overshoot of pressure on Earth’s life-giving systems, such as through climate change, ocean acidification and chemical pollution. But between these two sets of boundaries lies a sweet spot — shaped unmistakably like a doughnut — that is both an ecologically safe and socially just space for humanity. The twenty-first-century task is an unprecedented one: to bring all of humanity into that safe and just space.

What kind of currency, then, could be aligned with the living world so that it promoted regenerative investments rather than pursuing endless accumulation? One possibility is a currency bearing demurrage, a small fee incurred for holding money, so that it tends to lose rather than gain in value the longer it is held. The fact that demurrage is an unfamiliar term shows how accustomed we are to the ever-rising financial escalator that we ride – like knowing the idea of ‘up’ but not ‘down’, ‘more’ but not ‘less’. But demurrage is a word worth knowing because it could just feature in the financial future.

Imagine, for starters, if central banks were to take back the power to create money and then issue it to commercial banks, while simultaneously requiring them to hold 100 percent reserves for the loans that they make — meaning that every loan would be backed by someone else’s savings, or the bank’s own capital. It would certainly separate the role of providing money from the role of providing credit, so helping to prevent the build-up of debt-fuelled credit bubbles that burst with such deep social costs.