Artificial intelligence is improving rapidly, and a lot of people are worried that it will lead to massive job losses. In the past, technology mostly displaced workers doing routine tasks or manual labor. But as software becomes more sophisticated, there's a growing prospect that truck drivers, teachers, and perhaps even doctors could see their jobs replaced by a robot or a computer program. Ryan Avent is an economics correspondent for the Economist who has been thinking about the economics of automation for several years. He's a technology optimist -- he thinks software and robots really will massively boost economic productivity. But in a new book, he argues that this won't necessarily be good news for ordinary workers, since a glut of underemployed workers will make it harder to bargain for higher pay.

What do you think of when you hear the word "technology"? Do you think of jet planes and laboratory equipment and underwater farming? Or do you think of smartphones and machine-learning algorithms? When a grave-faced announcer on CNBC says "technology stocks are down today," we all know he means Facebook and Apple, not Boeing and Pfizer. To Thiel, this signals a deeper problem in the American economy, a shrinkage in our belief of what's possible, a pessimism about what is really likely to get better. Our definition of what technology is has narrowed, and he thinks that narrowing is no accident. "Technology gets defined as'that which is changing fast,'" he says. "If the other things are not defined as'technology,' we filter them out and we don't even look at them." He founded PayPal and Palantir, was one of the earliest investors in Facebook, and now sits atop a fortune estimated in the billions. We spoke in his sleek, floor-to-ceiling-windowed apartment overlooking Manhattan -- a palace built atop the riches of the IT revolution.