re: Why do people in Nordic countries consistently rank as the happiest and what can we learn?

Their happiness is polarized.

I read a post elsewhere from a Scandanavian who noted that during the pleasant Summer months when they have 18+ hours of daylight with warm weather everyone is running around outside, drinking and socializing, etc. But during the Winter they get depressed and hole up to escape the frigid cold and constant darkness.

The thing is these "happiness" or quality of life studies are always conducted in the Summer because they use students working summer jobs to collect and compile the data so the results are misleading because they catch everyone at peak fun time but if you ask them the same questions in January they will have a different answer.