Since Rogoff wrote, cash has been in retreat as a payment mechanism. In Sweden, for example, the demise of the paper krona seems within sight. The mobile payment system Swish dominates the small-denomination landscape. As anyone who has recently tried to buy a beer in Stockholm knows, you will remain thirsty if all you have is a wallet full of cash. And the COVID-19 crisis has given people another reason to steer away from banknotes. It was widely reported that the virus could be transmitted through handling them, prompting many outlets to put up “no cash” signs. In my village, even the traveling fish and chip van will now accept only a contactless card. In fact, there is little or no validity in that scare story. The World Health Organization has said there is no evidence that currency notes transmit coronavirus. The virus lasts just as long on plastic cards, and Christine Tait-Burkard, an infectious disease expert at the University of Edinburgh, said that cash is not a vector of disease “unless someone is using a banknote to sneeze in.”