It’s the biggest puzzle in the economy today: We are surrounded by technological advances, from artificial intelligence to robotics, but you can find no sign of it in wages or productivity. Apocalyptic warnings of jobs destroyed by automation look increasingly ludicrous amid a record streak of employment growth.

In the past year I’ve dug into this in columns and articles and concluded there isn’t a paradox: automation hasn’t advanced nearly as far as evangelists claim, and where it has, it’s often created more jobs than it’s...