The debate about the development of artificial intelligence can sometimes seem like a bungee jump off the Eiffel Tower.

One day the headlines are all about the existential threat that AI poses to humanity. The precise danger is not always spelt out but it is hard not to think of that Skynet program from the Terminator movies, which launches a nuclear war to eliminate its human masters. 

Another day, the forecasts are delirious with optimism. Take the view of Marc Andreessen, a US venture capitalist, who wrote recently that, as a result of AI: “Productivity growth throughout the economy will accelerate dramatically, driving economic growth, creation of new industries, creation of new jobs, and wage growth, and resulting in a new era of heightened material prosperity across the planet.”