“There is also nothing in economics that guarantees that the humans displaced from jobs by robots will end up with new jobs that pay as much as their former jobs, or pay enough to attain a middle-class lifestyle,” Freeman noted. “The main thing to fear today is not joblessness, but a future in which the earnings of workers are stagnant or falling (as robots take a greater share of high-productivity jobs), and the share of income going to the owners of the machines increases.”