For the 2012 ranking, 151 countries were compared, and the best scoring country for the second time in a row was Costa Rica, followed by Vietnam, Colombia, Belize and El Salvador. The lowest ranking countries in 2012 were Botswana, Chad and Qatar.
The Happy Planet Index (HPI) is an index of human well-being and environmental impact that was introduced by the New Economics Foundation (NEF) in July 2006. The index is designed to challenge well-established indices of countries’ development, such as Gross Domestic Product (GDP) and the Human Development Index (HDI), which are seen as not taking sustainability into account. In particular, GDP is seen as inappropriate, as the usual ultimate aim of most people is not to be rich, but to be happy and healthy. Furthermore, it is believed that the notion of sustainable development requires a measure of the environmental costs of pursuing those goals.