The growth of growth requires a different kind of person, one whose abilities, skills, emotions, and even sleep schedule are in sync with their role in the economy. We hear a sweetened version of this fact whenever politicians talk about preparing young people for the twenty-first-century labor market, and a slightly more sinister version from police officers and guidance counselors when they talk about working hard, flying right, and not making mistakes. It’s tough love, and young Americans are getting it from all sides. This advice is uncontroversial on its face, but its implications are profound. In order to fully recognize the scope of these changes, we need to think about young people the way industry and the government already do: as investments, productive machinery, “human capital.” If people have changed as much as other engines of productivity have over the past three or four decades, it’s no wonder the generation gap is so significant.