Norway is the happiest country on Earth,

while the US has slid to fourteenth, according to an in-depth report from the United Nations.

Researchers say six key factors affect each country 's happiness score :

income, life expectancy, freedom, generosity, corruption and social support among the community.

Income has a big effect on a country 's happiness,

but the report shows it's not everything.

For example, Norway 's economy didn't improve as much as America 's,

but Norway 's overall happiness ranked number one, while America 's dropped.

To improve happiness in the US, the report says politicians should focus on social reform,

instead of economic reform.

For example, from 2006 to 2016, the US corruption score jumped 16 %.

To offset that effect on happiness without improving corruption,

the average income would have to increase by $ 9, 000.

The decline in social support had an even stronger effect.

To offset that drop, the average income would have to jump by $ 29, 000.

The report notes if politicians really want to tackle the problem from the financial side,

there are two places they should start : campaign finance reform and reducing economic inequality.