The United States has dropped four spots in this year's World Happiness Report's annual ranking.
The U.S. dropped to the 18th spot in the ranking, which is published by the Sustainable Development Solutions Network, a United Nations initiative.
The report, released Wednesday, ranks 156 countries by their happiness levels. The rankings are based on results from Gallup World Poll surveys.To measure happiness, researchers used factors including income, healthy life expectancy, social support, freedom, trust and generosity.
Finland was ranked No. 1 in the report, with Norway coming in second and Denmark ranking in third.
The report also ranked 117 countries by the happiness of their immigrants.
“The most striking finding is the extent to which happiness of immigrants matches the locally born population,” John Helliwell, a University of British Columbia economist who co-edited the report, told The Washington Post.
“The happiest countries in the world also have the happiest immigrants in the world.”
The report found that the "attitude of immigrants is also important."
"If they are to find and accept opportunities to connect with the local populations, this is better for everyone,” the report found.