Relishing his nickname of “middle-class Joe,” he told delegates at the World Economic Forum annual meeting that the middle classes, the backbone of economies and democracies, now faced unprecedented threats from technological change.

“My call to action here is simple – embrace your obligation to workers as well as your shareholders,” Biden said, criticizing the recent trend by firms to return mountains of cash to investors by buying back stock rather than investing for the future.

Many of the world’s wealthiest and most powerful people are gathered in the Swiss Alps this week to discuss business and the wider state of the world, against a backdrop of tumbling stock markets and increased geopolitical tensions.

Those market ructions are dominating many conversations, although the challenges and opportunities of the so-called fourth industrial revolution – an umbrella term for robotics, artificial intelligence and hyperconnectivity – remain the official topic of this year’s meeting.

Many experts fear the next wave of innovations will destroy millions of jobs, hollowing out middle-income employment across manufacturing and the service sectors, even as new highly skilled computing jobs are created.

That, Biden said, represented a major threat to all members of society.

“When the middle class does well, the wealthy do very well, and the poor have a ladder up,” he said.