"Why should it be different this time?" That's the most common response I hear when I raise concerns about automation and the future of jobs, and it's a pretty simple rejoinder. The Western world managed the shift out of agricultural jobs into industry, and continued to see economic growth. So will not the jobs being displaced now by automation and artificial intelligence lead to new jobs elsewhere in a broadly similar and beneficial manner? Will not the former truck drivers, displaced by self-driving vehicles, find work caring for the elderly or maybe fixing or programming the new modes of transport?

As economics of that may well be correct, but as history it's missing some central problems. The shift out of agricultural jobs, while eventually a boon for virtually all of humanity, brought significant problems along the way. This time probably won't be different, and that's exactly why we should be concerned.

Consider, for instance, the history of wages during the Industrial Revolution. Estimates vary, but it is common to treat the Industrial Revolution as starting around 1760, at least in Britain. If we consider estimates for private per capita consumption, from 1760 to 1831, that variable rose only by about 22 percent. That's not much for a 71-year period. A lot of new wealth was being created, but economic turmoil and adjustment costs and war kept down the returns to labor. (If you're wondering, "Don't fight a major war" is the big policy lesson from this period, but also note that the setting for labor market adjustments is never ideal.)