When scientists and historians look back at the Great Pandemic of 2020, one of a handful of countries that will receive special scrutiny is Sweden. While much of Europe went into a lockdown from which it is only starting to emerge, Sweden has kept large parts of its economy open. It has conducted a vast experiment — some might say gamble — with its population.

Parts of the Swedish approach are familiar. People have still been asked to work from home if possible, avoid unnecessary travel and observe social distancing in public. Gatherings of more than 50 are banned; universities and schools for over-16s have closed. But primary and secondary schools have mostly stayed open; so too have shops, restaurants and factories. There is no test, track and trace system.

Globally, most countries have followed one of two paths as they wait for a vaccine or virus treatment. South Korea, Taiwan, Australia and New Zealand aimed to suppress the virus before it could spread. Borders were closed to those who might carry it, stringent test and trace measures adopted. A second group, some of which had failed to contain the virus, shut down economies to protect health systems and reduce or limit infection rates.