Every one of today’s smartphones has thousands of times more processing power than the computers that guided astronauts to the moon. And if Moore’s law – the theory that computing capacity doubles roughly every two years – continues to be accurate, tomorrow’s computers will be even stronger.

But Americans today dream less often of feats that computers will help us to accomplish; more and more we have nightmares about computers taking away our jobs. The optimism that many felt in the 1960s over labour-saving technology is giving way to a fearful question: will your labour be good for anything in the future? Or will you be replaced by a machine?

Fear of replacement is not new. Fifteen years ago American workers were worried about competition from cheaper Mexican substitutes. In 1992 US presidential candidate Ross Perot predicted that a “giant sucking sound” would be heard along the country’s southern border as soon as the North American Free Trade Agreement was signed.