So, happiness economics can help us get to these questions, and I'll try to give you some examples of this. Now, even though there's a lot of skepticism, originally about using this survey - surveys what people say make them happy. The number of reason that we are getting increasingly confident in doing so. One is that their consistent pattern - remarkable consistent pattern, determines well-being across large samples of people, across countries, across the world, and over time. Some of the basic things that make people happy, and I will show you some of these income health, marital status, employment status. Some of these very basic things are remarkably consistent across countries across world. So that gives us some sense that these surveys are picking up consistent patterns. And when we know what consistent patterns are, we can look how other things that very much more, affect people's well-being.