After a rare dip last year that knocked it a couple rungs below Switzerland and Iceland in the global rankings, Denmark is back on top as "the world's happiest country."

The annual report, prepared by the Sustainable Development Solutions Network (SDSN) and the Earth Institute at Columbia University, ranks countries on variables such as generosity, social support, healthy life expectancy, and freedom to make life choices. This year's top five once again included the Nordic countries, with Denmark, Switzerland, Iceland, Norway and Finland scoring the highest. Others in the top 10 included Canada (#5), New Zealand (#7) and Australia (#9).

Where does happiness in the U.S. rank? #13. According to Columbia University economist Jeffrey Sachs, director of the SDSN and lead author on the report, the U.S. needs to do more to address societal happiness.

"The message for the United States is clear," he told Reuters in an interview. "For a society that just chases money, we are chasing the wrong things. Our social fabric is deteriorating, social trust is deteriorating, faith in government is deteriorating."

What can other countries learn from those on top? As Russell McLendon shared in an enormously popular article on MNN, Nordic countries utilize a cultural concept known as "hygge" to sow happiness in the face of long, dark winters. While the word can be a bit hard to explain to outsiders, author Helen Dyrbye in her book "Xenophobe's Guide to the Danes," says it has much to do with people's behavior.

"It is the art of creating intimacy: a sense of comradeship, conviviality and contentment rolled into one," she writes.

As Starre Vartan adds, there are many "happy" countries that feature similar cultural concepts, including Norway's "Friluftsliv," Japan's "Shinrin-yoku," and Germany's "Gemütlichkeit."

In imploring countries to add societal happiness to their list of priorities, Sachs recommended a holistic approach for citizens that includes economic, social and environmental objectives.

"Rather than taking a narrow approach focused solely on economic growth," he said in a statement, "we should promote societies that are prosperous, just, and environmentally sustainable."