Denmark, Norway, Switzerland and the Netherlands are the happiest countries in the world, according to the U.N.-sponsored “World Happiness Report” released Monday by Columbia University’s Earth Institute. The report infers happiness using a number of social and economic metrics, measured using data from 2010 to 2012.

The very least happy countries, all in sub-Saharan Africa, are Togo, Benin, Central African Republic, Burundi and Rwanda. Syria also falls within the bottom 10. The United States ranks 17th of the 156 ranked countries, behind Mexico (16) and Panama (15).

The happiness metrics are highest in the Western, developed world: North America, Western Europe and Australia. But, as you can see in the above map, it's also quite high in much of Latin America and on the Arabian Peninsula. It tends to be lower in poorer countries, with some interesting outliers and sub-trends.

The science of assigning a concrete number to something as abstract as happiness is, unsurprisingly, neither straightforward nor uncontroversial. This report used three measures of happiness, each evaluated by Gallup polls: life satisfaction on a scale of 1 to 10, positive emotional state the prior day (Did you smile a lot yesterday? Did you experience enjoyment?) and negative emotional state the prior day (Did you experience anger or sadness?). The researchers aimed for a sample size of 3,000 people in each country over three years of Gallup polls — which, as they point out, risks skewing the data as events change within those countries over those years.