Happiest U.S. States Pinned Down | LiveScience

"Happiness measures

Their results come from a comparison of two data sets of happiness levels in each state, one that relied on participants' self-reported well-being and the other an objective measure that took into account a state's weather, home prices and other factors that are known reasons to frown (or smile).

The self-reported information came from 1.3 million U.S. citizens who took part in a survey between 2005 and 2008. "