The Swiss result, like the others in the top 10, was largely influenced by healthy satisfaction levels regarding social support networks, life expectancy, life freedom, and (especially, in the Swiss case) GDP per capita.
This years World Happiness Report ranks 156 countries by their happiness levels, and 117 countries by the happiness of their immigrants.
"In a division with such excellent teams, changes in the top spot are to be expected", he said. No country has held the title for two years in a row.
Nordic and European countries are normally at the top of the ranking. A higher value for migrant acceptance is linked to greater happiness for both immigrants and the native-born, by nearly equal amounts.
"The most striking finding of the report is the remarkable consistency between the happiness of immigrants and the locally born", said Helliwell, another co-editor on the report.
Wiking from the Happiness Research Institute said the USA had also seen declining "trust, generosity and social support, and those are some of the factors that explain why some countries are happier than others".
According to Jeffrey Sachs, a leading United States development economist who contributed to the report, "the U.S. happiness ranking is falling, in part because of the ongoing epidemics of obesity, substance abuse, and untreated depression". What is different for 2018 is that the poor United States of America, a country that went from 13th to 14th place last year, tumbled to 18th place this year.
John Helliwell, an economist at the University of British Columbia and one of the report's authors, said there were many similarities between countries in the top ten.
"US policymakers should take note". Germany came in 15th place, while the United Kingdom was 19th. "The U.S. happiness ranking is falling, in part because of the ongoing epidemics of obesity, substance abuse, and untreated depression".
The tiny country of Bhutan, which came in 97th place, brought attention to happiness as a metric for its people.
The report was released yesterday, days before the International Day of Happiness on March 20.
Israel's overall No. 11 position was helped by its health system; the report placed the Jewish state in sixth position for improvement in life expectancy, after Japan, Iceland, Italy, Switzerland and Canada. 156 countries were ranked in the report, based on factors such as citizens' freedom, gross domestic product, expenditure on health and lack of corruption.