In the first part of this mini-series, I surveyed how robots, automation and other productivity-enhancing technology is affecting industries at the heart of the economy as well as some more exotic science fiction examples. In the second part, I considered the “Solow paradox” — the strange combination of breathless innovation with stagnant labour productivity (though not so strange when you realise there is not that much investment in capital embodying the new technologies).

Today, we focus on the question of greatest political consequence. Who stole the jobs — was it robots or foreigners? Or less tendentiously, was the falling number of manufacturing jobs in rich countries caused by trade liberalisation or by automation and other productivity-enhancing technological change?

For it is largely manufacturing jobs we are talking about. The US is special in that overall employment rates (for all jobs taken together) have fallen since the turn of the century, and for longer than that among men. As Jason Furman and his colleagues have documented extensively, the US faces an especially aggravating version of a more common problem in which manufacturing jobs have not only disappeared but failed to be replaced by anything at all.