CAMBRIDGE – Since the dawn of the industrial age, a recurrent
fear has been that technological change will spawn mass
unemployment. Neoclassical economists predicted that this would
not happen, because people would find other jobs, albeit
possibly after a long period of painful adjustment. By and
large, that prediction has proven to be correct. Two hundred
years of breathtaking innovation since the dawn of the
industrial age have produced rising living standards for
ordinary people in much of the world, with no sharply rising
trend for unemployment. Yes, there have been many problems,
notably bouts of staggering inequality and increasingly horrific
wars. On balance, however, throughout much of the world, people
live longer, work much fewer hours, and lead generally healthier
lives. But there is no denying that technological change
nowadays has accelerated, potentially leading to deeper and more
profound dislocations. In a much-cited 1983 article, the great
economist Wassily Leontief worried that the pace of m