The Glass Cage: Automation and Us by Nicholas Carr Norton, 276 pp., $26.95

In September 2013, about a year before Nicholas Carr published The Glass Cage: Automation and Us, his chastening meditation on the human future, a pair of Oxford researchers issued a report predicting that nearly half of all jobs in the United States could be lost to machines within the next twenty years. The researchers, Carl Benedikt Frey and Michael Osborne, looked at seven hundred kinds of work and found that of those occupations, among the most susceptible to automation were loan officers, receptionists, paralegals, store clerks, taxi drivers, and security guards. Even computer programmers, the people writing the algorithms that are taking on these tasks, will not be immune. By Frey and Osborne’s calculations, there is about a 50 percent chance that programming, too, will be outsourced to machines within the next two decades.

In fact, this is already happening, in part because programmers increasingly rely on “self-correcting” code—that is, code that debugs and rewrites itself*—and in part because they are creating machines that are able to learn on the job. While these machines cannot think, per se, they can process phenomenal amounts of data with ever-increasing speed and use what they have learned to perform such functions as medical diagnosis, navigation, and translation, among many others. Add to these self-repairing robots that are able to negotiate hostile environments like radioactive power plants and collapsed mines and then fix themselves without human intercession when the need arises. The most recent iteration of these robots has been designed by the robots themselves, suggesting that in the future even roboticists may find themselves out of work.

The term for what happens when human workers are replaced by machines was coined by John Maynard Keynes in 1930 in the essay “Economic Possibilities for our Grandchildren.” He called it “technological unemployment.” At the time, Keynes considered technical unemployment a transitory condition, “a temporary phase of maladjustment” brought on by “our discovery of means of economizing the use of labour outrunning the pace at which we can find new uses for labour.” In the United States, for example, the mechanization of the railways around the time Keynes was writing his essay put nearly half a million people out of work. Similarly, rotary phones were making switchboard operators obsolete, while mechanical harvesters, plows, and combines were replacing traditional farmworkers, just as the first steam-engine tractors had replaced horses and oxen less than a century before. Machine efficiency was becoming so great that President Roosevelt, in 1935, told the nation that the economy might never be able to reabsorb all the workers who were being displaced. The more sanguine New York Times editorial board then accused the president of falling prey to the “calamity prophets.”

In retrospect, it certainly looked as if he had. Unemployment, which was…