HOW much is an American dollar worth? The glib answer is exactly one buck. But that is far from the case if the dollar in question is one of Zimbabwe’s “bond notes”, the world’s newest currency that is not officially a currency.

Zimbabwe adopted the US dollar as its official currency after the spendthrift regime of President Robert Mugabe printed so many of its own notes that it caused hyperinflation in 2008. The economy briefly stabilised; but old habits die hard. Last year the government again spent far more money than it raised, much of it on imports, causing scarce greenbacks to flow out of the country.

By the end of the year there were so few dollars still circulating that banks were limiting withdrawals to $50 a day, crippling the economy. The central bank decided to issue a new currency, called “bond notes”, pegged to the American dollar. Two months on, the new notes, nicknamed “bollars”, are rapidly losing their value. People have discovered that they are not, in fact, convertible into real dollars. So they cannot be used to pay for imports—a real problem in a country that does not make much. Shops accepting bond notes can use them to pay local wages and suppliers or deposit them in their local bank accounts (denominated in US dollars). But if they want to pay for imports to restock their shelves, they still have to queue for real dollars.

So desperate are shops for hard currency that they are offering discounts of as much as 50% to customers who hand over greenbacks. Some petrol stations now have separate pumps where the price of fuel is lower for customers who pay with hard-currency cash instead of using a debit card. A number of shops in Harare have resorted to indicating two or three different prices for the same item—a US dollar cash price, a bond-note price and a third price if one pays by card.

Black marketeers have been quick to help out. Some are offering to convert bank balances into real dollars at premiums ranging from 5% to 30%.

The big supermarket chains are not allowed to offer cash discounts or discriminate against customers who use bond notes or electronic cards. Instead they have simply put up their prices. With inflation surging, the bond notes are proving to be exactly what many Zimbabweans feared they might be: the horribly resurrected zombie of their dead cousin, the Zimbabwe dollar, which burned itself out almost a decade ago. Unless the country changes tack, more economic misery looms.