According to the World Happiness Report, Finland is the happiest country in the world. The report is produced by the U.N. Sustainable Development Solutions Network. It uses criteria such as gross domestic product per person, and healthy life expectancy, as well as surveys. "We asked two kinds of questions. So one is about the life in general, life evaluation, we call it. How is your life going? The other is about mood, emotions, stress, anxiety, ” said report co-author Jeffrey Sachs.