Notwithstanding illusions of a better past, by every measure associated with well-being—education, health, literacy, sanitation, wealth, lower unemployment—generally speaking, America is better off today than ever before. Yet, we rank 23rd in the Happiness Index, falling out of the top 20 for the first time. How can that be? Despite the six o’clock news and that fear-jerking story making the rounds on social media, even violent crime is down dramatically. Highly publicized and disturbing events...