Interestingly my ongoing Google search for the source of the Happiest Nation on Earth Survey (see below) is throwing up another interesting find. Apparently at times the distinction also belonged to Nigeria. That if you recollect is a fellow country near the top of the Corruption Perception Index published by Transparency International. Hmmm... that's a food for thought ain't it? Corruption = Happiness!
Maybe we can ask Dr. Steven Levitt the author of Freakonomics to find a co-relationship. Actually on a side note do look at his blog http://www.freakonomics.com/blog/