What really predicted fertility, the authors find, are attitudes about work and family.The world’s richest countries typically have the world’s lowest birth rates. The highest-income people in those wealthy countries on average have the smallest family sizes. Those two facts conflict with the broad perception, especially among lawmakers, that Americans aren’t having babies because they’re worried about how expensive kids are. So may the results of a new study out today, which finds that the more career-oriented individuals and wealthy societies become, the more their fertility declines. “Highly work-focused values and social attitudes among both men and women are strongly...