Some people think it's a law that when productivity goes up, everybody benefits. There is no economic law that says technological progress has to benefit everybody or even most people. It's possible that productivity can go up and the economic pie gets bigger, but the majority of people don't share in that gain.

Electricity is an example of a general purpose technology, like the steam engine before it. General purpose technologies drive most economic growth, because they unleash cascades of complementary innovations, like lightbulbs and, yes, factory redesign.

G.D.P. is not a measure of how much value is produced for consumers. Everybody should recognize that G.D.P. is not a welfare metric.

There are lots of examples of routine, middle-skilled jobs that involve relatively structured tasks, and those are the jobs that are being eliminated the fastest. Those kinds of jobs are easier for our friends in the artificial intelligence community to design robots to handle them. They could be software robots; they could be physical robots.

When goods are digital, they can be replicated with perfect quality at nearly zero cost, and they can be delivered almost instantaneously. Welcome to the economics of abundance.