A new study suggests the happiest people in the world live in Norway. (Norway?)

Every year, the United Nations Sustainable Development Solutions Network issues a report listing the happiest countries in the world. Most years, it's the Scandinavian countries that top the list. In fact, this year, Norway is followed by Denmark, Iceland and Switzerland.

So what is it about a cold, somewhat remote northern European country that makes people there so happy? There are at least four factors.

1. They have a lot of money.

Money can't buy happiness, but it sure doesn't hurt that Norway is the sixth wealthiest country in the world (in terms of gross domestic product per capita). You don't need to be an expert on the Norwegian economy to understand that the country's fortunes changed for the better 40 or 50 years ago, when they found oil in the North Sea.

"The top countries, you can see, have societies which are not at each others throats. But also they have high GDP per capita," Dr. Jan-Emmanuel De Neve, one of the UN study's associate editors told Time.

Of course simply having a robust economy isn't everything. The United States ranked 14th on the study, but we're falling--despite the fact that our economy is getting better. Instead, it's what they do with the money and how it affects people's security and contentment.

2. They have bad weather.

This one doesn't make sense at first--I would have thought that a place like Aruba, with perfect weather, would be happier than cold and snowy Norway. Heck, the slogan on license plates in Aruba literally read, "One Happy Island."

But some researchers say the dark, cold climate in places like Norway makes people happier in the long run, because survival requires "greater mutual support," And it turns out that the colder weather and longer nights associated with Scandinavia might actually help bring communities together.

"There is a view which suggests that historically communities that lived in harsher weather were brought together by greater mutual support," another of the study's co-editors, Dr. John Helliwell said.

Besides, it seems the Norwegians have a positive attitude about the negative weather.

"The first yar we lived here, I kept my son home from school because of a snowstorm," Kristin Ohrn Nilsen, an American living in Norway, told me in an email. "The teacher was completely puzzled. Here there is a rugged, 'Viking' type mentality and they have a saying, 'Det er ikke noe som heter dårlig vær, bare dårlig klær,' which means, 'There is no such thing as bad weather, only bad clothing.'"

3. They have lots of community spirit.

It's not just the cold, of course, but the combination of geography and security also lead to people developing long-standing relationships with each other.

"Norwegians do not move often, and often pass their family homes down to their children. My husband bought his family's home. Therefore, in many cities, especially small cities, people have a strong network of family , and I think they have a strong sense of identity," Nilsen told me. "They have a term, 'sted bundet,' directly translated [as] 'place bound.' And many people consider themselves 'sted bundet, and [would not] consider moving."

Actually, Nilsen said, there's one more Scandinavian term that captures the feeling: "hygge."

"The Danes have taken credit for, but it is just as much Norwegian," she said. "It is basically a state of well- being, coziness, ambiance. 'Hygge' is a feeling, an atmosphere and an action. You can be a "hyggelig' person, or you can describe a cabin as 'hyggelig,' or it can be used as a verb: 'Let's hygge ourselves with a ... a meal, a visit, a book, etc."

4. They don't worry--because they have economic security.

Remember that high per capita GDP, driven largely by oil revenue? In Norwegian society, they spend the country's money on purchasing security for almost everyone.

"We pay a maximum of $300 per year to doctors, emergency rooms, etc," Nilsen told me. "Once you hit that amount, you receive a 'fri kort' ('free card'), and don't pay any more the rest of the year," she wrote, and listed other benefits that would be unheard of in the U.S.: all children's medical expenses, childbirth, five weeks paid vacation.

"Everyone receives a pension at 67 ... even women who have chosen to stay at home, and have not worked outside the home," she continued. "Free education through university level. (We do have high taxes though.)"