And to what extent is the danger of government-sponsored happiness leading to an interference of personal liberties?
I think anything the government does tends to raise that question. But one of the things that the research shows is that personal liberties are one of the important contributors to happiness. So if you believe in happiness research, you ought to pay close attention to that, because it could affect the objective that you're trying to reach.
Is there a limit to the amount of happiness that government can help to foster?
I think Samuel Johnson said it best: "How small, of all that human hearts endure, that part which laws or kings can cause or cure." I think what he was getting at is that government can't do a lot about making human relationships stronger.
What lessons can leaders of developing nations—who have economic growth on their minds—take from this book?
There's a lot of controversy over whether growth contributes to happiness. But one thing everyone agrees on, at least to a certain point, is that building a stronger and more prosperous economy increases happiness. It's only when you become reasonably prosperous as a nation that there's dispute over whether continued growth does very much for happiness. For example, on average, Americans have not become happier since researchers first started collecting statistics in 1950. But our gross national product must have tripled in real terms over that period. On the other hand, it's also true that richer people are consistently more happy than poor people. And richer countries tend to be happier than developing countries. So there's no doubt that you'd want to help the developing countries get better. But one of the big unexplained puzzles in this research is: How do you reconcile those pieces of evidence and weave them into a consistent pattern? And I don't think anybody has solved that one yet.