Maybe it's the chocolate. Or its reputation for neutrality. Or how much it's known for investing in the health, education and employment of its people. Whatever the reason, Switzerland is the world's happiest place, according to an analysis released Thursday of more than 150 countries.

The third World Happiness Report identifies Switzerland as the country with the best sense of well-being, taking the lead from Denmark, which fell to third after ranking first in the last two reports. Iceland came in second, and Norway and Canada placed fourth and fifth. Meanwhile, the United States comes in at No. 15, two spots higher than it did in 2013, when the last report came out (though still lower than the 2o12 report, when it ranked 11th).

Click on a country below to see how happy it is:

The report is produced by the Sustainable Development Solutions Network (SDSN), a group of leaders from academia, government and the private sector. The network was launched with the United Nations in 2012, though the U.N. is independent from both SDSN and the report.

The network based its rankings on surveys by the Gallup World Poll between 2012 and 2014. It also analyzed how six variables—including GDP per capita, healthy life expectancy and perceptions of corruption—help to explain each country's score.

Part of the network's aim in creating the report is to encourage policymakers to do more to measure and improve citizens' happiness. Richard Layard, one of the report's co-authors and the director of the Wellbeing Program at the London School of Economics, said in a press conference that "our argument lying behind the whole report is policymakers should be making the happiness of the people their goals, which is not a new idea."

Layard went on to reference Thomas Jefferson's quote that "the care of human life and happiness and not their destruction is the first and only legitimate object of good government."

Layard also mentioned German Chancellor Angela Merkel as "the most interesting world leader on this," citing a wellbeing forum she held in 2013. The report highlights efforts by her and other governments to track happiness, such as a grant won by the city of Santa Monica, Calif. to study happiness among its citizens and an open letter written by Prime Minister Sheikh Mohammed bin Rashid Al Maktoum to United Arab Emirates federal employees.

Jeffrey Sachs, another co-author of the paper and the director of the Earth Institute at Columbia University, said he hopes U.N. members will include some measures of happiness when they meet in September to adopt Sustainable Development Goals. "I'm actually optimistic that we'll get there," he said.

The report also looked at the biggest changes in happiness from the three years before the global recession (2005 to 2007) to the three most recent years (2012 to 2014). Nicaragua, Zimbabwe and Ecuador saw the biggest increase, while Italy, Egypt and Greece saw the largest decline. The score in the United States fell slightly over that period.

And what about the least happy places on Earth? The bottom five were Rwanda, Benin, Syria, Burundi and Togo, where the overall score was less than half that of Switzerland's.

Read also:

Like On Leadership? Follow us on Facebook and Twitter, and subscribe to our podcast on iTunes.