Will Wilkinson describes a recent article as "easily the funniest happiness research paper ever" on his Happiness and Public Policy blog. The British Medical Journal is by Kaare Christensen, Anne Maria Herskind, and James W Vaupel: Why Danes are smug: comparative study of life satisfaction in the European Union (PDF). It's all about having low expectations. Here's the key quote:
The key factor that explains this and that differentiates Danes from Swedes and Finns seems to be that Danes have consistently low (and indubitably realistic) expectations for the year to come. Year after year they are pleasantly surprised to find that not everything is getting more rotten in the state of Denmark.
This finding is supported by Danish news coverage of the 2005 pronouncement by Ruut Veenhoven, Dutch Professor of Social Conditions for Happiness and head of the World Database of Happiness, that Danes are the world’s happiest people. The headlines in Denmark ran: We’re the happiest “lige nu.” The phrase “lige nu,” which can be translated literally as “just now,” is a quintessentially Danish expression redolent, indeed reeking, of the sentiment “for the time being, but probably not for long and don’t have any expectations it will last.”