There is a variety of reports, and they have very different vectors.
The report we use is The World Happiness Report published by the United Nations Sustainable Development Solutions Network.

(The first report in 2012, the second in 2013, and the third on April 23, 2015.)
The 2015 report:


Switzerland now at the top, followed closely by Iceland, Denmark and Norway. All four 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.

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