According to the latest World Happiness Report, issued by the Sustainable Development Solutions Network (SDSN) on Apr 23 2015, the happiest countries in the world are Switzerland, Iceland, Denmark and Norway. Four top countries have average scores between 7.5 and 7.6, and the differences between them are not statistically significant. The rest of the top 10 (in order) are Canada, Finland, Netherlands, Sweden, New Zealand and Australia, all with average scores above 7.28.
Comparing the country rankings in World Happiness Report 2015 with those in World Happiness Report 2013, there is a combination of consistency and change. Nine of the top 10 countries in 2015 were also in the top 10 of 2013. There is more turnover, almost half, among the bottom of the list. Most are in sub-Saharan Africa, with the addition of Afghanistan and a further drop for Syria and Ukraine because of warfare. Greece, Cyprus and Albania also showed a drop in the happiness level due to economic turmoil.
Happiness scores data come from the Gallup World Polls. The rankings are based on answers to the main life evaluation question asked in the poll. This is called the Cantril ladder: it asks respondents to think of a ladder, with the best possible life for them being a 10, and the worst possible life being a 0. They are then asked to rate their own current lives on that 0 to 10 scale.
Resulting happiness scores are closely associated with the personal income levels. Generally, people, who live in countries with the larger GDP per capita, tend to be happier. However, the wealth is not only factor that affects happiness. Some countries show significantly higher happiness scores for given per capita GDP (this is typical for Latin America states e.g. Brazil, Panama, Venezuela, Costa Rica, Uruguay, Argentina). Countries that facing worsening economic conditions (such as highly indebted European countries and some in Eastern Europe) and the states with a low level of respect for human rights and high corruption show the opposite tendency (see the bubble chart at the bottom of the page).
Source: World Happiness Report 2015