In his book The Future of Money, Lietaer points out – as the government did yesterday – that in situations like ours everything grinds to a halt for want of money. But he also explains that there is no reason why this money should take the form of sterling or be issued by the banks. Money consists only of “an agreement within a community to use something as a medium of exchange”. The medium of exchange could be anything, as long as everyone who uses it trusts that everyone else will recognise its value. During the Great Depression, businesses in the United States issued rabbit tails, seashells and wooden discs as currency, as well as all manner of papers and metal tokens. In 1971, Jaime Lerner, the mayor of Curitiba in Brazil, kick-started the economy of the city and solved two major social problems by issuing currency in the form of bus tokens. People earned them by picking and sorting litter: thus cleaning the streets and acquiring the means to commute to work. Schemes like this helped Curitiba become one of the most prosperous cities in Brazil.

But the projects that have proved most effective were those inspired by the German economist Silvio Gessell, who became finance minister in Gustav Landauer’s doomed Bavarian republic. He proposed that communities seeking to rescue themselves from economic collapse should issue their own currency. To discourage people from hoarding it, they should impose a fee (called demurrage), which has the same effect as negative interest. The back of each banknote would contain 12 boxes. For the note to remain valid, the owner had to buy a stamp every month and stick it in one of the boxes. It would be withdrawn from circulation after a year. Money of this kind is called stamp scrip: a privately issued currency that becomes less valuable the longer you hold on to it.

One of the first places to experiment with this scheme was the small German town of Schwanenkirchen. In 1923, hyperinflation had caused a credit crunch of a different kind. A Dr Hebecker, owner of a coalmine in Schwanenkirchen, told his workers that if they wouldn’t accept the coal-backed stamp scrip he had invented – the Wara – he would have to close the mine. He promised to exchange it, in the first instance, for food. The scheme immediately took off. It saved both the mine and the town. It was soon adopted by 2,000 corporations across Germany. But in 1931, under pressure from the central bank, the ministry of finance closed the project down, with catastrophic consequences for the communities that had come to depend on it. Lietaer points out that the only remaining option for the German economy was ruthless centralised economic planning. Would Hitler have come to power if the Wara and similar schemes had been allowed to survive?