"It's really quiet," said the proprietor of Oxford's best falafel stall when I popped over to buy lunch on Monday. It is even quieter now. Meanwhile, my wife e-mailed friends to ask if we could help: Both of them are doctors and they have three children and a parent undergoing treatment for cancer. "Thanks. We will be in touch," came the reply. No time for more. It may be quiet for the falafel man, but not for them.

There, in miniature, is the economic problem the coronavirus pandemic has caused, even in its early stages. For everyone who is overworked, someone else has little to do but wait. The supermarkets have struggled to meet a rush of demand for some goods, but that will pass. "We are not going to run out of food, so chill," says Massachusetts Institute of Technology professor Yossi Sheffi, an authority on supply chains.