Aside from the success of "The Killing" TV series and their 2013 Eurovision song contest victory, the people of Denmark have something else to celebrate: they are the world's happiest people.
That's according to the latest "World Happiness Report" compiled by a group at the United Nations, which used experts in fields such as economics, psychology and statistics to help measure the well-being of people across the world.
The United Nations Sustainable Development Solutions Network considered six variables when determining a nation's happiness: its gross domestic product per capita, its citizen's length of healthy life expectancy; whether citizens had someone to count on in times of trouble, perceptions of corruption, prevalence of generosity and freedom to make life choices. The report said that 75 percent of international differences in happiness could be explained by these variables.
(Read more: The world's best places to live 2011)
Based on its formula, four out of the top five countries for happiness were Scandinavian, with Denmark leading the pack, followed by Norway, Switzerland, the Netherlands and Sweden.
The United States ranked seventeenth, while the bottom five countries of the 156 surveyed all came from Africa: Togo, Benin, the Central African Republic, Burundi and Rwanda (in descending order).
Jeffrey Sachs, co-editor of the "World Happiness Report," said that Scandinavian countries ranked very highly across all six key variables, while the U.S. was let down on perceived corruption and lower health conditions.
(Read more: Where Dothe World's Happiest Consumers Live?)
The report said that quality of life has improved most in Latin America and the Caribbean over the last year. Countries that have been worst affected by the financial crisis -- notably Greece, Spain, Portugal and Italy -- suffered the worst declines in happiness, as well as those regions experiencing political and social instability, such as the Middle East and North Africa.
The report also noted a drop in happiness in South Asia, where despite economic growth and greater generosity, there was a perceived decline in social support and the freedom to make choices.
For the world as a whole, there was a 0.5 percent increase in happiness between 2007 and 2012. But don't take this as reason to rejoice: the report describes this slight improvement as "insignificant".
(Read more: Companies withthe Happiest Employees)