Adrian White, from the University of Leicester’s School of Psychology, analysed previously published data to create a global projection of subjective well-being: the first world map of happiness.
The research is based on the findings of over 100 different studies around the world, which questioned 80,000 people worldwide.
The top 10 "happiest" countries:
5. The Bahamas
Denmark ended up at the top to "its wealth, natural beauty, small size, quality education, and good health care". At the bottom were the Democratic Republic of Congo, Zimbabwe and Burundi.
The U.S. ended up on the 23rd place, the UK on 41, China is 82, Japan 90, and India an unhappy 125.
Here is the map of happiness around the world (the darker red, the merrier):
The original research paper can be found here.