Norway has been named the happiest country on Earth. Could this be cause Americans are getting sadder, and it takes more than just money to be happy?

Norway vaulted to the top slot in the World Happiness Report despite the plummeting price of oil, a key part of its economy. Income in the United States has gone up over the past decade, but happiness is declining.

The United States was 14th in the latest ranking, down from number 13 last year, while the United Kingdom was ranked 19th. Germany was ranked 16th and France 31st.

“It’s the human things that matter. If the riches make it harder to have frequent and trustworthy relationship between people, is it worth it?” asked John Helliwell, the lead author of the report and an economist at the University of British Columbia in Canada (ranked number seven). “The material can stand in the way of the human.”

Norway moved from number four to the top spot in the report’s rankings, which combine economic, health and polling data compiled by economists that are averaged over three years from 2014 to 2016. Norway edged past previous champ Denmark, which fell to second. Iceland, Switzerland and Finland round out the top five.

What works in the Nordic countries is a sense of community and understanding in the common good.

Still, you need some money to be happy, which is why most of the bottom countries are in desperate poverty. But at a certain point extra money doesn’t buy extra happiness, Helliwell and others said.

The Central African Republic fell to last on the happiness list, and is joined at the bottom by Burundi, Tanzania, Syria and Rwanda.

The report ranks 155 countries. The economists have been ranking countries since 2012, but the data used goes back farther so the economists can judge trends.

The rankings are based on gross domestic product per person, healthy life expectancy with four factors from global surveys. In those surveys, people give scores from one to 10 on how much social support they feel they have if something goes wrong, their freedom to make their own life choices, their sense of how corrupt their society is and how generous they are.

While most countries were either getting happier or at least treading water, America’s happiness score dropped by five per cent over the past decade. Venezuela and the Central African Republic slipped the most over the past decade. Nicaragua and Latvia increased the most.