Economists warn of “Nokia-style” overdependence on a single sector.

It’s not the first time this small Danish town boomed with the times. The question for Mayor Martin Damm is when, or even whether, the bust will come again.

In the 1920s a bet by a businessman on a new shipyard in Kalundborg went bad. Decades later, a locally famous hair roller-maker — called Carmen Curlers — faded with the 1960s fashion for wavy hair.

Now, a few hundred meters from Damm’s office, a new giant is rising amid a thicket of cranes and clouds of churned-up dust: a massive factory extension for Novo Nordisk, one of the world’s biggest insulin makers and the company behind diabetes drug Ozempic and anti-obesity treatment Wegovy.